If you are concerned about buying refurbished products, then you can always purchase an after market warranty. They are not perfect and sometimes you have to fight for them but in some cases, they come through better than manufacturer warranties. Just read the fine print. I've had pretty good luck with refurbished items I've bought but for the more expensive items that have lots of electronics or other hard to maintain parts, I have purchased warranties for them. Also, I've only bought warranties that cost much less than replacement or even repair. For instance $30 for a $400 item. Some will say that warranties are a waste of money and perhaps it is since most are never used. That said, if you are faced with a refurbished deal where you can save $300 and the only thing holding you back is the warranty, then the $50-100 warranty might be worth it for peace of mind alone. In the end, you still save $200. Let's face it, manufacturers build warranty costs into the price of new items so at least you have a choice when you buy refurbished. Also, look into your credit cards and see if any of them provide warranties for items purchased. Particularly AmEx was known to do this. All of that aside, NXR seems to have a pretty good following. Most people say they are a great value. Good luck.

Given your choices I'd definitely go with the DCS - I've had the DCS range for 5 years and it's great. Burners are fantastic - great highs and extremely low simmers. Good convection oven and fantastic infrared broiler. Bluestar is a great product too - many, many happy users - but as you've pointed out, it has open burners. Now, open vs. sealed burners is a controversial issue. I LOVE sealed burners, particularly on the DCS, very easy to clean - but others will tell you that open burners are easier because you can take the pieces over to the sink to clean them and there are drip trays to catch things that fall through the burners - not for me. Personally, I'd stay away from Viking - there have been too many bad reviews regarding it's reliability although there are some happy owners on this forum.

I now have delivery and installation of my DCS "30 AG range AND the DCS "30 convection oven (the new one with knobs). Love, Love, Love them both! DH is over the moon as well. Have not really had a chance to cook with either much as we're still fitting the granite (blue pearl) countertops over the (Kohler) kitchen farm sink so plumbing and fixtures are not complete and I'm still camping out. But so far both of these are knock-out appliances! I'm blown away with what the convection oven can do (in terms of cooking methods) and anticipate bringing my culinary skills to a whole new level now that I have all kinds of precision at my fingertips. I'm beyond happy!

Have a DCS 30" dual fuel. No complaints about the fan, but that's a subjective issue. My Zephyr hood is noisier. In general, a very nice, heavy duty appliance. The bead blasted stainless cooktop requires patience when cleaning. You can get it perfect but it takes elbow grease and multiple steps using oven cleaner and sturdy cloth. Don't use any abrasives like Barkeeper's Friend or Scotchbrite pads. You'll scratch it and there's no way to repair it. When you first get it, wipe the cooktop down with some acetone before using it. They use sticky tape to hold down the burners in shipment and the glue residue from that tape will burn right into the cooktop. And it's extremely difficult to get off. The acetone will help you avoid that issue.