I own and love my Optima 2000...it is installed on my Kimber Classic Custom and has been flawless for the last 3000 rounds.
The bad news is that I originally installed the Optima 2000 on my Kimber and had a helluva time adjusting the sight, and shortly thereafter the sight said 'Nighty night" I called Tasco, started to explain what happened and the rep interupted with, " send it back for replacement" Two weeks later I received a New Optima 2000 that was easy to adjust and has given a flawless performance ever since.
This sight is incredilbe. You set it once and forget it...if you change ranges, you can either use Kentucky windage, or a simple turn on an allen screw will place your round right in the 10 ring.
It is small, light , very accurate, and easy to adjust.