We downsized from a 30 foot American Star 5th wheel to a 6501 this year. I'm always fiddling around with the trailer and trying to improve things. The 6501 was well thought out and the V front really is a great help. I like the day cruiser type dinette. On the road, it seems impervious to headwinds. We tow with a Dodge Cummins 3500 SRW and get 17.4 MPG into a 26 mph headwind on flat road with the truck A/C on.
We use only an anti-sway bar and a brake unit. A WDH would put too much truck weight back on the trailer axle. The hitch should put 12% of the weight on the tow vehicle, and I am hard put to accomplish that and stay anywhere near level, so the anti-sway bar keeps us stable while we tow with the trailer level. We only keep light stuff in the storage and depend on the truck bed for heavy items. It is nice because with the 5th wheel I couldn't use the short truck bed for very much.
On the 6501 I replaced the rear lights with nice LEDs, and found that there is no structure to sink a wood screw into, unless you find an aluminum piece of frame and screw into that. Everything that is randomly screwed into a wall is held by sheer numbers of small screws into the paneling. I prefer to use a nylon spreading insert which works real well for most things.
All the 6501 appliances and accessories are excellent. The TV antenna is high gain, the A/C is good, the fridge is totally automatic and the water heater is great. Watch movies with a USB drive. We were attracted by the stand up shower, and the size of the bed. There is no inside clothing storage but I solved that by putting nice cabinet doors in to replace the netting.
Sure we have to crawl over each other at night to use the bathroom but it beats sleeping alone.