I found out on my 700-4 that if your hauling anything but light material the dump bed ...doesn't. Its more suited to allow you to get to the engine. with the ROPS in the way the bed can't be filled except by a shovel. 1000-5 isn't any better. It will hold my camping gear and recovery gear aloft when I have the bed raised up but thats its limitation. When I have to move material I rent a skid steer or my neighbor will bring his 50hp tractor with a loader over or box blade. Its not generally amounts I would want to move by hand in a SxS.
I ended up finding a scrap trailer that I made into a yard trailer, its not pretty or perfect but it does the work and its easier to get around the property with.
Where we ride there is enough room 98% of the time for a 1000 but we are also limited to local spots in general. Where the draconian 50" limitation is a plenty I can see the 500 being much more useful.