I purchased the original Blowfish around 1999 and it's been my go-to pack for day climbs and in-bound skiing. The zipper finally went after 16 years and I purchased this latest (and as I understand discontinued) Blowfish.
First off, I'm not sure there were any improvements over the original! The improvements that I can see are that it is about 25% larger than original (you can argue pros/cons for that), reflective material, and helmet hooks. I don't bike much with it, so the last 2 improvements don't really affect me.
It comes with a 70oz bladder, wish it had a 3L option, but you can easily fit a 3L bladder in if you have one.
This review was written in the old system and had content requirements that are different than reviews written today.