Real quick now, dont think about it too much - what's your preferred flip up rear sight?
I will add that I'm looking to get one sooner or later.
I'll also add that I really dont like the magpul mbus, but that's just my preference.
I used to have a troy diamond diopter flip rear which was pretty nice, even though I didnt get to use it much before selling the rifle it was on.
Last, I realize that what you like & what you actually use can be 2 different things, so try not to give the question too much thought.