Just note that the GoLite Jam is a frameless pack so, as mentioned in the other posts, you don't want to carry very much in it.

For me, I can't carry more than 7-8 lbs. in a frameless pack because I have extremely sensitive shoulders. I have to have a frame, load lifters and excellent weight transfer to the hip belt. I can't recommend my pack, though, because it was discontinued 5 years ago. The nearest to it is the Six Moon Designs Starlite, but that one is quite a bit bigger. The Starlite is also discontinued.

Packs I'd look at if I were replacing mine would be the ULA Circuit, Elemental Horizons Kalais, and possibly one of the new designs (not yet on the market) that Brian Frankle (founder of ULA) is coming up with for Six Moon Designs (no, I haven't seen them; just curious).

Since pack fit is almost as individual as shoe fit, my comments are definitely in the YMMV category!