The Rocket pack has a shorter back than the Saber. It is designed to fit above webbing belt kit. I had one and found I got severe lower back pain. The build quality was pretty good, the material is not as heavy as the Saber, but tough enough. The padding was good, and the pockets fit on a yoke just fine.
At the end of the day though, a pack is for carrying things, and if you can't carry it comfortably, its not worth having. I am not tall, but I couldn't use the pack for packing things. The Saber is longer and carries more comfortably, but still not as well as some of other packs.
I bought the Rocket pack without having got to try it on. If you are going to buy a pack without trying, be sure you can send it back if it doesn't fit.
Being lost is a state of mind, not a state of place.