I have two red dots.
1. Aimpoint CompM4 and
2. BSA cheapo
Frankly, other than battery life and the size of the dot, I see little difference between the two. I've had the BSA for 5 or 6 years longer than the Aimpoint which I bought about 4 years ago. The BSA takes a beating because my kids use it a lot. Nevertheless, it keeps ticking and doesn't seem to ever loose its zero.
Aimpoints are like expensive watches or expensive pens. They look good, they perform well, and they have a high wow factor. For the money, however, they are a rip off.
I'll never buy another Aimpoint but will most certainly buy a few more BSAs.