So much of it could be summed up as: preference + budget = trigger
I wouldn't use anything other than AR Gold if I could, but you can't have $250 triggers in every AR! I end up switching my main lower around to different uppers most of the time.
I've always felt CMC has some great sub $100 options, and oddly, I will never use a Geissele SD3G for 3 gun, it just has too much movement and is too heavy for me to comfortably shoot any groups zeroing, or shoot long range, but maybe that's me?
Hiperfire has some good ones too for the money, but I don't think I'll EVER pay more than the 250 for an AR gold on another trigger.