I've been usng a Redz Tranzport Series Bag for several years now and it's one of the largest paintball bags I've seen (I haven't come across the "Paintball Bodybags" yet). What I like about it:
Heavy Duty, lockable zippers on all major compartments
A lid with smaller pockets stitched in
Wheels and telescoping handle
Heavy gauge nylon outer skin
Internal Dividers for main compartment
What I don't like about it:
Not long enough for my Woodstalker Ion
Internal Dividers aren't configurable- they aren't long enough for my T9.1 and not wide enough for my Woodstalker Ion (and it's warp feed).
Internal nylon for pockets frays and get's stuck in the pocket zippers.
I've come to believe it really depends on your gear. The nice thing about those giant plastic tubs is that you can make your own dividers, or if you pack creatively, you may not need dividers at all.