There are some very capable F150's if you choose the correct options, however they will be at their weight limits and you should avoid towing while hauling a camper. Once you get to the F250, the payload may not look that much more but there is much more truck underneath you. You will have a full floating axle and larger brakes along with a heavier frame. The F250 is really a F350 that has been tagged with a lower GVWR so it falls under restrictions present in commercial use and in some residential zones. I call the 3/4t trucks the sleepers of payload capacity because the can be ordered with options to meet the capacity of the next class yet still hold a sticker that belies their capability.