Ford F350 all day long - they're the #1 seller for a reason, especially against the bowties. As mentioned above, don't bother with a 3/4 ton; price will be almost the same, ride will be no different (once you air down tires when not towing) but you'll gain at least 1k in payload.
Honestly, all RV's in that price range are equally junk, and that's just the nature of the industry. You have to spend a lot more to jump up into the Outdoors RV/Nash type of lower volume boutique brands, but even those have build quality issues.
Just look for features that you want. After owning a few, here are my criteria for minimum build quality:
- Azdel construction for walls to avoid issues with water if/when the roof leaks
- Fully walkable roof - many are very soft between trusses, but some are fully covered in plywood. This just translates to being a bit more overbuilt.
- Look at payload/GVWR ratio. If a huge 5er only has 1500 lbs of cargo capacity, it's axles/frame are undersized and it'll break sooner.
- Axle weight ratings that are equal to the GVWR or close is a good sign that it's built right. Many rely on the ~20% hitch transfer and slap on the cheapest axles you can find.
- Look for upgraded suspension (CRE 3000 I think?), not just leaf springs bolted to fixed shackles
- Tires can be changed out, but Goodyear Endurance is a good sign
- Fresh water tank capacity is huge for me when I'm boondocking. I love toyhaulers just for the simple fact that they usually come with onboard generators and 100gal water tanks
- Triple towing is a PITA. Consider a toyhauler. Your kids will be fine on their huge drop down queen beds. Layout isn't the best, but you'll get a more beefy trailer overall. In my experience we never spend much time in the camper beyond sleeping...
- Few 5ers actually have rear hitches rated for towing any more than a couple hundred pounds, check for that.
- Integrated solar is awesome, but if you only camp at RV campgrounds not important
- Rear camera is a gamechanger, but usually easily added
- Get the smallest one you can tolerate. If you boondock, pulling a massive camper is horrible, and asking for trouble. In fact, I don't recommend 5th wheels for navigating off-pavement. Very easy to get off-camber and smash bed rails/tailgate into the 5er cab.
- Heated/enclosed underbelly is key
I ended up with a bumper pull toyhauler. I don't like the interior layout, but it hauls my 4 seater SXS, sleeps plenty, has onboard genny/fuel station, 100 gal water tank, and can be pulled up some gnarly twisty roads if needed. 5ers would not work at my spots with any modern truck with high bed rails (would need a utility bed conversion).
I also went with a long bed F350. Not much worse at all than my previous short bed F250, but way more stable towing. Also has a 48 gallon fuel tank with a nearly 1,000 mile range. IMO the fuel tanks in short beds are too small.