If I was going to spend 700+ on an optic, the ACOG would be a first choice. I've only had the chance to look through one, mounted to the shop owner's AR, but it was the clearest sight picture I've ever seen. The red triangle was just the right brightness, no matter the lighting, and the optics seemed sharper than my eyesight. It would be excellent for dusk and dawn hunting, too.
I'd like to get a look through one of the Trijicon Accupoint variable-power scopes, I'll bet they're excellent, too. Haven't read any online buyer's complaints about Trijicon . Five-star rated.