I've got both. I have much more experience with the 2.5 dot though. I recently bought the 7.5 delta to have an extra and will find something to put it on eventually. But after seeing both and messing around with them, i like the 2.5 better for uspsa. There's a lot of theory behind the delta; zero for long shots at tip of triangle and aim center triangle for close stuff etc. But frankly, for uspsa, its just more simple to use the dot. The delta gets complicated and even if you can learn it and be very fast, i think it is an unnecessary hoop to jump through.