Hey There,
We are very new to RV'ing, but here is what we've experienced thus far. We have an '06 Chevy Crew Cab with a short bed and a 36' fifth wheel, we had a sliding hitch installed, as Gary mentioned above. I don't always Need to put it into 'maneuvering mode', but I'd say 95% of the time I do just to be safe. Have not had a problem with it yet. However, on our first trip camping where we would have to take a generator, I was real concerned that I'd have enough clearance for the 6500watt generator in the truck bed. I had enough, but just barely. In retrospect I would prefer the long bed for the carrying space, but for maneuvering, the short bed with the sliding hitch works great!!!
4x4 versus 2 wheel drive, I like having the 4x4 because where we store it, you have to drive thru a large well maintained field to get it into it's parking spot. No other way around it, I must pull it thru. Lately here in Houston it's been raining a Lot, if not for the 4x4 I would have been stuck in the mud several times. I have not needed the 4x4 at any of the camping areas I've been to, but we've also only been to a few areas close by. The down side to the 4x4 for Me has been that the truck sits higher then a non 4x4, as a result I have a bit less clearance between the bottom of the fifth wheel and the bed rails. This is not a problem going down the road, it pulls great. But the hitch is designed to pivot a few degrees left to right, this allows the 5er to get awful close to hitting the bed rails when pulling thru uneven camping areas or country roads that have real steep dips going into a left or right hand intersection. As I said, we have not hit yet, and may never do so, but it's been a concern.
If I had to do it again, I'd get the 3500 over the 2500 just for safety, but our setup works great thus far. Also, we have no intention of traveling the country with it until retirement (and that's a good 20+ years away). At which point we won't have this setup anymore. The longest trip we plan on taking (and have done) is 300 miles from Houston to Ft. Worth for the NASCAR races, and that is all flat land driving. ;D It was a blast!!!
In a nut shell, we like our Crew Cab 4x4 short bed w/ the slider hitch and big 5er. But I also wanted to voice the concerns or issues that we have thus far experienced with our setup. Other folks here have a whole lot more experience than I do in this area, we got our first setup back at the end of July this year. We're pretty much newbies.