I have the first generation Bushnell HOLOsight and the Aimpoint Comp M-XD. As soon as I can get the jing together, I'm getting an EOTech 551/552.
I LOVE the reticle on the HOLOsight. The dot/circle reticle is soooo much faster than the 3 MOA dot on the Aimpoint.
The only problem with the first generation HOLOsight was durability. The laser emitter is not fully encapsulated, so any blockage of the laser would kill the sight picture. The N-cells also didn't last very long.
The new EOTech is the real deal. The laser emitter is self-contained. The military models come with the ruggedized hood, which was hard as hell to find on the original HOLOsight. It's shorter and lighter and now can take AA batteries for decent battery life.
Only one thing. I have no illusions that the EOTech, as a HUD-type sight, is as durable as my Aimpoint or any other rugged closed-tube sight. If you are gonna be deployed in Afghanistan or some other inhospitable area, the Aimpoint M2/ML2 might be a better bet.
Justin