I was very happy with the Xcharger Xtreme on my 2006 convertible - put the car into the mid 12's and was very consistent. But the Xcharger isn't going to win any dyno sheet comparison nights because it isn't going to put the most RWHP. But I had a couple of friends with the procharger and vortech that couldn't take me at the track (they needed a driver mod). Another friend has the Powerhouse turbo kit on his car and although I could get the jump on him he always ran me down, and his car is in the low 11's now with that.
I had a chance this past weekend though to ride in a car with the new upgraded TVS blower for the Xcharger. Definitely had more power and torque than my Xcharger Xtreme (with the MP90 blower). I'd like to get one of those to the track and see what it would do.
As far as ease of installation, that is the Xcharger. Reliablility - put the Xcharger on my car at 90,000 miles and sold it with 203,000 on it still running mid 12's. The new owner has it up to 212,000 and still running strong.