I well know the "love em or hate em" legend of Rage. And until this year, I've used Rage successfully for at least 5 years.
This year I lost a doe, after my shot went wide right and gut shot her. I was ANGRY, and it was a 15 yard shot!
I shot some practice heads afterward, and they were dead on. I had one broadhead left in my quiver and shot it at the target, and missed completely at 20 yds.
I still can't explain it, though both the broadheads that I had this year were 3+ years old (although were never fired). I always checked them by hand to make sure they were clean and still worked and clipped to the O-ring properly, and they did.
I switched to the old muzzy's and haven't looked back. And here's why I don't think I'll ever shoot a mechanical again: I can't practice with the live broadheads. Even if the practice heads and regular heads shoot the same, you will never know if the broadhead opens the way it should until it is flying at a live deer. My confidence is just not there anymore. (and as a note, I never changed the blades on my rages. I always threw the heads out after taking a deer, and just hunted with a fresh head)
Conversely, with fixed blades, I don't like shooting my hunting heads at a target much and dulling blades, but I will ALWAYS shoot them at least once. Just to ensure they fly true and don't have a flaw. I suppose I miss Rage's huge entry/exit holes and big bloodtrails. But the confidence is an easy trade off