DiN1:
Depends on what else I bring on the trek. I usually have an EOS 30D with 17-85 lens in the middle compartment (lens down), which leaves room for a portable hard drive and a couple filters under the lens. On one side is a 100-300 zoom and on the other either a camcorder (Canon Optura Xi) with mic setup and tele adapter, or a pair of primes, like a 28 and a 50. Could probably fit another short prime with rearranging the interior pad things. Memory cards go in the little organizer on the flap of the bottom compartment. Then in the top part I put batteries, power blocks, straps, maybe an extra tee shirt and some bars (depending on where I'm headed). Water in the side pocket. I strap my tripod to the bottom using the attachment points built-in there. The computer (currently a Toshiba Portege) goes into the slot in the back, along with a sketchbook. And we're good to go.
It's a lot of stuff, but like the Lowepro, the strapping arrangements make it pretty comfortable. Comparing the Rover and the Adventure, it looks like the Adventure is a little taller overall, and has a taller padded section for the gear.
Oh, I should mention that all the lenses are in some type of inner pack-either a neoprene fitted cover, a mesh bag (Eagle Creek I like) or something like that. And I sometimes will throw in a PnS like the S2. Love the accessability of the rear-side compartment for the computer; better than the others I've had with top access.
HTH.
---Ritch