I currently use a grubstake medium for virtually all my on and of bike needs and was considering a chrome ivan bag. Anybody have info on both and able to clear up my only concern - which is that both bags are going to hold the same amount of stuff. My only complaint with the grubstake is that it isn't waterproof which puts my laptop and college books at risk in rain storms.

Haven't a clue, but since it looks like you are willing to drop some $$, maybe you should take a look at the Mission Workshop bags.

Used to have a grubstake. Didn't really like it for long.

Check the reload flight pack. Will hold more than the grubstake, and 100% waterproof, and has a sternum strap. Been using for about 3 weeks now and really like it.

Or the mission workshop bags.

Man those Mission Bags are HARDCORE! When I start needing a backpack more, I know what my next one is going to be. Thanks for posting that. As far as biking related, the only waterproof bag I can recommend is the Ortlieb roller, the QL3 system is much better than the current (coming out sometime this year) and would work very well on the back.