I have the Highmark vest and really like it. Fit and finish is top notch with snow pulse. Extremely comfortable, I can do all the maneuvers I used to do with a pack no problem. Weight is a little on the heavy side until I put it on then like everyone else says, you don't feel it cause of the dispersion. BUT it has enough storage to make me feel like I'm Carrying around a snap on tool box and a 30 pack of coors (only made that mistake once) so I keep it light and simple.
Front pockets are awesome. It's so nice to grab the small things you use frequently without taking off the pack or un packing the sled.
I also find the vest to be much easier and faster to put on/ take off. Because
1. HUGE arm holes and large flaps to easily slide each arm into without the skinny pack straps becoming twisted or somehow glued to your back while you desperately reach around and grab at a strap that isn't actually there.
2. No long chest and waist buckles to become wrapped and lost on the shoulder straps just 3 quick buckles and a zipper for the vest.
3. Can easily be slipped on and off in full riding gear. Never have a problem.
Also I can now drop a base layer because the vest is, well a vest. Warm layer with added protection.
This is only my point of view and my opinion on why I like the vest over the back pack style, everyone is differnt. One ridding buddy wants a vest like mine, another still wants a pack. To each his own I'm only stating why I like them.
Side note: on any avy pack be double sure the puncture needle is FIRMLY back in the reset position before screwing a new air canister in otherwise the night before a ride you might have a nice surprise red balloon explode in your face.