The DX3 line are built on Freightliner M-2 HDT (Heavy Duty Truck) cab chassis. These Class 7 HDTs are rated at 33,000 pounds GVWR. They have a TRUE tow capacity of 20,000 pounds! When you check some RVs, the "rated" tow capacity cannot be achieved because of a restriction on tongue weight. You don't have that problem with a DX3. Air suspension along with professional air seats make for a smooth ride. You're sitting up high (like a professional trucker) and, have a GREAT view of the road. A three camera system makes it easy to see what's going on on both sides of the coach and in the rear. With the engine up front, future service costs will be less than on diesel pushers. The 37RB floor plan features a bath and a half. I LOVE the fact that, on the two slides, nothing important moves. The residential refrigerator, washer / dryer, sink, toilets, shower, stovetop etc stay put. Propane, water supply and drain lines do NOT have to move. In many RVs, this is not the case. Another feature I love, is that with the two slides fully retracted, I can still walk from the front cab all the way back to the bedroom. I have full use of the three door fridge, the stovetop and the mid-ship toilet. I can sleep in the king size bed too. You can't do any of this on many other RVs unless you open the slides.
Drawbacks: Super C Class motorhomes tend to have a lot of coach extending past the rear axle. The DX3-37RB has about 13' aft of the rear axle. You need to keep that in mind when making turns (I got used to it quickly). Dynamax installs two engine batteries and two house batteries. The residential fridge, when running off the inverter, will deplete the house batteries in 24 hours so, you need to be either 1:plugged int shore power, 2: running the generator or 3: running the diesel engine. I replaced the two 12V house batteries with SIX 6V batteries and, now have four times the amp hours! The next time I'm in the southwest, I'll look into having solar panels installed. Although there is a lot of storage space inside and outside, there is no pass though storage (although there is a spot near the back where I think I can fabricate a rack to effect 6'+ of storage for a long item).
Bottom line: The DX3 models are built on a heavy duty commercial truck. These trucks are built for trucker use and, truckers expect HDTs to be capable of delivering over 1,000,000 miles of service. IF I live to be 300, I might wear it out.