I've had both in front of the wheelwell and behind. I'd have to say they each have their advantages. On my old Dodge, I installed it between the wheelwell and front of the bed for it's safety. I use my trucks for both scrap and firewood when not towing, and felt behind the wheelwell was too vulnerable to damage. Granted, at that point I had a gooseneck trailer that required getting in the bed to lock the coupler and install the chains. I ordered my new F350 with the 5th wheel prep, and the connector is between the wheelwell and tailgate. It's had a few close calls, but I haven't mashed it yet. Will be much easier with a 5th wheel since there is no reason to get in the bed to hook it up. Working on buying a dump trailer though so I can stop taking chances with it and beating the hell out of the bed...............................
2013 F350 dually
2015 Palomino Puma 351THSS Premier Edition
2015 Nights camped 15
2016 Nights camped 5