Actually 650lbs is pretty light considering the stock 3rd gen bed weighs over 400lbs alone, and the bumper weighs another 45lbs.
:bull crap: I find it really hard to believe the stock beds weighs that much. Pat and I lifted my tacoma bed off just the 2 of us, and I know I cant arm curl 200 lbs, like I did half the bed. And it has a spray in liner that adds wieght also. Plus the more storage and stuff you add to a flatbed the more
you end up bringing that just adds wieght in the end.