Great comments from everyone so far.
I had a couple of other things to consider.
First, I have towed a lot of things with 4 different vehicles. From a 16 ft hybrid to a 48 ft, 21,000lb race car hauler. I'm on my 3rd diesel truck. An F250, F350 SRW and now an F350 long bed, crew cab dually. My current camper is a 31 ft 5th wheel that weighs about 9,000lbs. Any SRW truck will tow it fine. Diesels are better... always. I also towed a 43 ft toy hauler 5er that carries a Miata race car. It goes about 14,000lbs. And the 2 car enclosed car hauler is 48ft long and just over 21,000 lbs with both Mustangs, parts, tools and spares.
Personally, a DRW isn't needed until you get to about 12,000. Over 12,000 I think it gets uncomfortable with a SRW truck. Under that, a DRW feels more stable, especially in cross winds and rough pavement, but it certainly isn't required.
My trailer before my current 5er was a 33 ft TT. It weighed about 7,000. (No slides) Overall, I prefer a 5er. They do tow a little nicer. They just feel more stable with the pin weight over the axle instead of hanging on the bumper. Absolutely no sway either with a 5er and therefore no need for sway controls or weight distribution hitches. 5ers are also much easier to hitch up once you figure out the ideal pin height. Again, no WD hitch, lining up on a ball or sway bars.
Backing up is different. Can't say one is easier than the other, but a 5er reacts differently when backing because of the pivot point (hitch) being over an axle instead of 4 or 5 ft behind it.
If you are looking at a trailer AND a truck, get a matched set. Decide which trailer meets your needs (and budget), then decide how much truck you need. Remember to consider a loaded weight for the trailer. I always found that taking the "as delivered" or "dry weight" of the trailer and adding 1000-1500 lbs for "stuff" was a good estimate for the amount of junk I brought along. Then find a truck that has a tow capacity at least 10-20% above the trailer weight.
While diesels are unbeatable for towing heavy, there are a number of F150 size trucks that have tow ratings over 10,000lbs. If the vehicle is a daily driver and you only tow a few times a year, the easier maneuverability and better (cheaper) gas mileage is worth the smaller truck. My 8500 lb, F350 diesel gets 15-16mpg (non-towing) driving it back and forth to work. One of my staff has a new F150 with the V6 EcoBoost. It has a 12,000 tow rating and gets 23 mpg driving to work.
And last, DEFINITELY go to an RV show. It is the best way to do side by side comparisons and see a large number of manufacturers (and floor plans). I have a pretty good idea what I want in a next trailer. DW just got a new job with a really good salary increase. I'm still waiting until the winter RV show to decide if I really want a new camper.
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