I know that this tread is a bit old, but thought I would toss in some input. Simplyjeff is right on. Sinuous is NOT a quality compromise. My family has been in the furniture business for over 40 years and we have had major accounts with all types of suppliers especially those in foam and coils. I have actually toured a coil factory in NC that makes a "fake" 8 way hand tie coil simply because people ask for it, but the truth is that coils are good enough now that they don't need to be tied. Here is the long and short of it. Some people only carry lines with 8 way hand ties, that is fine, but they will only promote that as "The" way to make furniture. It is like using a rotary telephone when you have a cell phone in your pocket. It will work, won't drop a call, but when it comes down to it, it basically does the same thing. The major issue with sinuous is how it is installed. If it is installed correctly, i.e. the number of coils per sq in, the gauge and secured then it will not fail. There is a reason that some call it "No Sag." Because it will not sag. When it comes down to comfort a lot of that has to do with the density and IFD of the foam that you are selecting for your core/wrap of your cushions. One person stated above that quality=weight, but then mentioned MDF wood. Quality and MDF should never be in the same sentence when it comes to furniture. Whether it be kiln dried or air dried woods, hardwood is the best way to go when constructing a frame. Some companies use pressed wood to cut cost and still charge you 3k for a chair because they have a brand name and sell through retailers who all need to make a markup on each piece to make it worth their time. We use sinuous in almost all of our seating applications, so I may be the other side of the bias, however the in 40 years we have been in business, the number of issues we have with seat failures is basically less than 1%. Tankertoad, I saw that you were talking about foam density, 2.0 is a great density, but also check the IFD which is the amount of weight it takes to compress typically 25% of the capacity of the foam, sometimes they give you the 75% number as well. The quality of foam is just as more important as deciding whether 8 way or sinuous is the way to go. General rule of thumb 1.8 and above on density in sufficient and over 30 IFD is typical for residential use. 10/90 down is great if down is your thing, 5/95 down is also fine if that is what you are looking for. Down cushions and back pillows are what they are. They are going to be soft and have a great feel, but they will need fluffing from time to time. You will lose fill capacity much quicker with down than you will with a softer density foam wrap over time but this is really a preference thing. We can achieve the same crowing and appearance with foam as with down, and it will last longer. Typically high end foam only will shrink less than 5% over 10 years. Overview, you asked the right questions. There is no sense covering a "bad" frame in expensive fabric. It is like putting lipstick on a pig. Still a pig. But as far as Sinuous vs 8 Way, both work, it is more of a feel thing and honestly if you are feeling those coils then the foam selection is incorrect. Either way you should never "bottom out" in either. You should never feel the bottom of your seat. Coils will wear out faster than sinuous. It is a spring and springs wear. That is a fact! When it comes to selecting down, again a preference thing, just make sure that you realize that it will need some routine upkeep, but that in a standard 3 cushion maybe 86" length sofa with typical seat depths you are looking at a 1k to 1500 upgrade at retail costs. But if you like chardonnay then drink chardonnay. This is your choice. The main reason that we choose to use sinuous is because of consistency. You get a much more consistent seat surface over the span of your sofa, especially if you are looking at a matching loveseat or chair. If you use the same gauge and same number over same area you get the same seat. This may be harder to achieve with 8 way as the number of coils may need to be reduce or a smaller gauge may need to be used in order to "fit" the drop in unit in the seat deck. I hope that this information helps, maybe for future furniture selection. Remember the questions you asked are the right ones and need to be answered when you are looking at selecting your furniture. When it comes to warranties, I always remember "Tommy Boy" the movie. "Hey, if you want me to take a dump in a box and mark it guaranteed, I will. I got spare time. But for now, for your customer's sake, for your daughter's sake, ya might wanna think about buying a quality product from me." My Best

Both Sir John and Freethinker99 have given excellent analyses on the various options available. On the other hand consumers must constantly balance questions of quality vs. cost. There is no doubt that 8 way hand tied coils and 5/4" solid wood frames are superior to drop-in coils (or no-sag) springs and plywood frames. On the other hand a well-built plywood frame sofa with an inexpensive no-sag spring system, costing many hundreds of dollars less, can still be expected to last at least 10 years. Cushions and fabric are far more likely to wear out long before the frame and springs. On sofas retailing for under $1500 by far the most popular type of cushion construction is a 1.8 density HR (High Resilience) polyurethane foam with a polyester fiber wrapping. This type of cushion construction will typically hold up for only 3-5 years before beginning to lose its shape and resilience. If you are looking for a sofa to hold up for 10 years you will need to upgrade your cushions. The two most popular upgrade options include spring-down or high density foam cushions. Spring-down cushions are constructed using a coil spring system inside which is surrounded by foam and typically topped with a down/feather/fiber blend. Another popular cushion upgrade option is one using a high density foam. The higher the cushion density, the more foam is used per cubic inch and the greater the cushion durability. Although a 2.0 density HR (High Resilience) foam is a definite improvement over the standard 1.8 density, I would recommend a 2.2 density or higher if you want your cushions to last 10 years. Fabric durability is the other primary concern for a sofa lasting 10 years. Although there are literally hundreds of variations that can affect a specific fabric's durability, in general look for thicker, heavier fabrics that are tightly woven. Keep in mind that a fabric's cleanability may also be a factor as a "dirty" or badly stained couch is unappetizing no matter how long you have owned it.

I see what Rmanbike is saying about the joinery being mortise and tennon and then corner blocked, triple dowled, glued, and screwed. Perhaps they are using a bit of both depending on the area of the frame. You might want to ask the store for clarification and then let us all know as this sounds kind of interesting. Regarding the spring some manufacturers put another rail in the front of the front rail of the frame and then this rail is dropped down about an inch. This is usually used with a plywood frame. Then they use a clip called an RJS clip. This clip is shot on with a gun. Some frame shops if they use the rail have a machine that puts the clip on the frame. I haven't heard of any company still using this system. Southern furniture used to do this but I am not sure if they still do this. They do this so you can arch the spring and give you a softer seat. Some manufactuers also then drive the spring into the frame with a hammer. But I don't know of anyone that still does this. I can't see how you could glue in this type of spring. In my opinion the spring action from a single attachement point would be the same as far as durabilty. Here again I think I would ask for clarification on this point as what they are saying is confusing.

Mitchel gold use three types of suspension depending on the item. They primarily us a no sag sinuous spring, which is essentially s shaped wires stretched across the frame attached by clips to the sides. They also use "Pirelli Webbing" which are bands of elasticized cloth woven in a checkerboard. The webbing suspension is used in Europe. Here it is commonly found on dining room chairs. Personally I would not choose it. What they refer to as "Rigid Sheet Webbing" is really a material called Propex. Propex is the polypropylene material used under an 8 way hand tied suspension in which the steel banding used to support the 8 way hand tied springs rest on. I have not heard of using this for a suspension. I think they just use this for small chairs and I doubt they are using this in the sectional you are looking at. I would think they are using a sinuous spring in the sectional. A Propex only suspension would be very hard on your cushions as it wouldn't give and in my opinion it would cause excess pressure on the cushions causing them to wear out. They say they used hardwoods and plywood's in their frame but they go on to say the frames are cut by a computer "C and C router". You can't cut a 5/4 hardwood frame with a router very easily so in my opinion they are predominately using a plywood frame. A hardwood frame such as Maple or Poplar or Ash is preferable and the most durable. They do talk about environmental issues in construction, a 5/4 hardwood frame is naturally good for the environment as it is just wood and does not contain any glues or manmade materials