Having had both... I never found the long bed to have any huge benefit. It takes a bit more creativity to get it all in the shortbed, but I've never had to leave something behind.
My common load:
5th wheel hitch (slider) still in bed, with my 37" spare in front of the hitch laying flat (I have to slide the slider back, lay the tire down, then slide it back up). Underneath the tire in the dead space, I have a lug wrench, jumper cables, bottle jack, etc. I have my hilift jack mounted to the side of the bed. Right behind my slider hitch I have a ~2' wide locking box where I keep my air compressor, another bottle jack, a 3"x30' tow strap, a bunch of tie downs and bungees, rags, random tools, etc. This still leaves me plenty of room to put a dirt bike on each side of the hitch, my big gear bag with my riding gear, 2 gas cans and a ramp but the tailgate wont quite close. I can pull a trailer behind it like this though.
If I need a touch more space, I have a tire-gate I can put on the truck that moves the tire to the tailgate and allows the tailgate to close with the bikes in the bed. Then I can put my sons little 4 wheeler and my other sons little PW50 dirt bike up front sideways and halfway on the 5th wheel hitch.
With the 5th wheel hooked up (obviously no dirtbikes haha), similar loading except I throw in another hi lift, 2 ice chests, a 100' tow strap, some chains, an extra spare for my 5th wheel (gets strapped to the top of my 37" spare), my fire-pit cooker, my disc cooker, and then i fill the voids with fire wood.
Ill try to find some pics to post up.
--Jeff