My sole experience was with a '99 2500 5-speed 4x4 that I just flat loved. I drove it for about 5 months and hated to give it up. Highway mileage with a 1500 lb "interesting" camper shell was 23mpg. I liked the 24 valve engine, the original owner had never had any problems with it and it had decent power with noticeable turbo boost coming in around 1300 rpm. Truck had 167,000 miles and seemed like it would keep running forever.

I think the 3500 is too much truck for what you are going to use it for.

R.