I've used a lot of different hydration packs for mountain biking - Camelback, DaKine, Deuter, Wingnut. The Raptor's been my favorite of the bunch. The storage is well thought out, the dividers are useful, and there's plenty of room in the 10 for a long ride. It easily fits 2 extra tubes (I'm tubeless, but I also ride with enough "Anyone got a spare tube, I pinched again!" guys) a multitool, a Leatherman, shock pump and tire pump, a couple of Clif bars and gels, and a small rain jacket just in case.
The Raptor is the best fitting pack I've ever used once gravity takes over. I liked the Wingnut fit and concept, but I never did get totally used to it on the downhills.
Long-term, I've got some reservations about the bladder, specifically the mouthpiece. My Dakine pack used a Nalgene bladder, and while the Raptor doesn't have the leak prone disconnect on the bladder side, it's still got the same mouthpiece that seemed to leak like a sieve after three months or so. I'll update in the future if the same thing happens here.
The Raptor is also pretty good at not heating up your back too much, but not as good as the Deuter with the rigid hammock they use. I'm more than happy to make that tradeoff for the organized space and the downhill fit, which were both places the Deuter was just not good.
And that little magnet? Genius. I HATE having the hose flopping around and tapping my knee on a climb.