I've messed around with mechanicals for a few years and decided to give the Rage 2's a try last season. I've had good luck with them so far. Taken three deer with no problems with failure or small wound channels. The most impressive result was an entry wound with a nearly 3" diameter cutting! Exit was about 1.5" diameter. Deer bled quick and dropped after only 20 yards.
I did hit one in the spine and was thrilled with the result! I've made spine shots with the fold-back blades and had the blades snap or fold all the way back on impact. Not a terrible thing when the barrel of the broadhead still severs the spine, but they don't like bone. The Rage shattered two vertebrae and still left a good exit wound.
The primary downfall is the way the blades are held "closed" during the shot. There's a rubber o-ring around the base of the barrel that a little barb on the back of the blades snaps under. They're easily knocked loose and I've given myself numerous little cuts on the finger tips getting them re-armed.
As far as mechanical broadheads as a concept, I feel that they are excellent for use on deer-sized game. They track better and shoot smaller groups than traditional broadheads in my setup. Many of the faster bow shooters swear by them. I'd never consider them for elk or large game, but for dropping a whitetail at 30 yards, they're the bomb!
Of the three different mechanicals I've tried, I have to say that I like the Rage the best. Unfortunately, they're pretty pricey, so loosing one really hurts.
J-