When I got the Diamante ($1400) last summer, it would have been about $300 more to go to the Optima ($1700). At that time, I didn't think it was worth it, as the only "noticeable" difference was the split cutlery tray (where the left side can come out for tall glasses) and the display on the front was angled up. Going from Q2 (Diamante) to Q3 (Optima) of sound level wasn't that big of a deal. So that's why I went with the Diamante. But if I were to buy the new Futura models, I might splurge the extra $300 and go with the Dimension since the lower two baskets are better, and it has the 3D cutlery rack (which I think is pretty cool). It also has the Sensory Dry and the new Intensive wash mode, which I think is for dishes/pots/pans that have heavy baked/dried-on food. So for $300, I think all those options together may be worth it. The jump from the Dimension to the Diamond is probably around $1000, so I wouldn't go that far unless you're well-off can can afford "the best" money can buy. The Diamond does add the cool LED lights on the inside, the auto-open/close door, Q5 sound level, and a ton more wash programs that anyone would ever use (just like the La Perla).

@fauguy - I live in NE Fort Lauderdale, zip code 33308. After testing the water from my kitchen tap with a Sofchek water hardness test strip I picked up at the shop where I purchased my Miele DW supplies (a vacuum shop at Commercial & 18th Ave.), I set my DW settings to 15 gpg. If I end up having a Miele tech out here at any point, I will ask them to recheck the water hardness. Our DW allows me to set the water hardness at the precise setting, as opposed to setting based on ranges. Unfortunately, I don't have much confidence in information obtained from my local water utility department; that's why I tested the water hardness myself. BTW, I spent time on the phone today with one of the founders of NY Minute, the company I booked based on your excellent recommendation. In my case, the installers left much to be desired. The lead installer spoke only broken English and communicating with him was a challenge. I put down layers of beach towels on the floor surrounding my dishwasher and the kitchen sink, yet the lead installer repeatedly ignored my requests to set his wrench, drill, etc. on the towels, and I repeatedly heard him dropping his tools onto the floor. As a result, I found multiple areas of damage (divets) in the marble flooring when they finished. Additionally, I just discovered that it appears I am missing two pieces of my dishwasher installation. Earlier today when I phoned Miele tech support to ask about how to tell when a cycle was complete, I learned that in addition to the audible setting (which had been disabled when our DW was installed) there should be a "prism" mounted to the underside of the granite counter, just above the Miele control panel on the DW, that serves to reflect the red indicator light that illuminates and flashes when a cycle has completed. According to the Miele tech, this prism is shipped in the box with the DW and comes with a corresponding stainless steel frame. Both pieces are to be attached by the installer. NY Minute's install team did not install, discuss, or leave me any such parts. Although my keyword search of the PDF manual does not indicate any matches for "prism," I discussed this with NYM today and also have a call in to the Miele Territory Manager who handles Miele issues for the dealer from whom we purchased our DW (FL Builder Appliances).

What you (and fauguy) say in point 3) may be true for newer Miele dishwashers, but mine specifically says to not use the side mounting screws at all if the opening is wider than the recommended 23-5/8", because of leakage concerns (from bending/separating?). Maybe the new models are stiffer there, but I think I would add shims at least where the screws go, to bring the width down to 23-5/8"

Can't help you with salt - our water hardness doesn't require this - but remember reading it in the manual and sighed a sigh of relief It will be worth it in the end. I didn't formally test the water but we get a water report 2 times per year from the city - so used this. I also think there is an auto setting in the machine but not sure. Using a Miele certified rep increases your warranty to 2 years - otherwise most installers can do a Miele.... That being said - I did buy the extended warranty and used it to return the first lemon after 4 years - turns out the installer did some things incorrectly which toasted the machine in time - not to scare you but things can be done wrong. So after swearing off Miele, I studied the internet, read every review on every dishwasher, looked at the repair rates, talked to several high end appliance stores and decided - I just had the one lemon. I purchased a new one (I received a full refund) and bought my new one which has been terrific. Last night I tossed in the dinner dishes, a grungy baked on muffin tin, pots, pans, etc - everything came out clean. I am currently using the Miele tablets without additional softener as they have softener as part of the cube. I might try cutting them in half for general use. If you go with an extended warranty - I would go with the Miele version and not the local appliance store version - then they send out their repair folks. I had a minor problem with mine and explained the problem. They sent out the repair guy with the replacement part in hand - no 2-3 trips! The repairman didn't like how the top rack was working - one of the flipper bars popped off, so he said - let me just order you a new top rack and it showed up at the door - he would have come back if I needed but was easy to swap out. Everything comes out clean - I sometimes have a small drip ring at one spot on the glasses if they are at an angle which I just wipe off with a soft cloth. If they are straight up, not a problem - but some of my glasses will collect water in the base, so I tip them a bit. Enjoy!!