I agree. The Ashley Express Sights (
www.expresssights.com) are largely recognized as the fastest for target acquisition. Think of it as a big "i" with a large dot over the "i". I have them on ALL of my defensive pistols. Also see Andy Stanford's book, "Surgical speed shooting: How to achieve high-speed marksmanship in a gunfight" (2001) Paladin Press. See Chapter 5 "Aiming"
Some people criticize them as not being that accurate (although my 1.5" groups have not suffered-my varilux multifocal lenses have done more to drop my effectiveness); but that depends on the shooter.
You have to get used to them, but they are simple, fast, and designed for you to acquire the target under stress... As an interesting note, I read that they are patterned after the sights on the big-bore rifles that African professional hunters carried to kill charging (and really, really pissed) cape buffalo and lion after their clients missed the shot...