I load 4.3 gr of unique behind a 124 gr Frontier CMJ, it also works very well with 124gr Cactus plains LRN as well.
My manual lists 4.0 to 5.0 gr of unique with a 124gr FMJ bullet.
I found under 4 gr. of unique to be a little "dirty" but 4.3gr is as clean as any other powder that I have tried.
I worked up a load starting at 3.75 to 5gr in .25 gr increments, and 4.25 was the best, so I tested a batch from 4.1 to 4.5 in .1 increments, and 4.3 is the best group in my pistol.
It works well in my M&P9, M-213 & in my buddies CZ-75. With my M&P I get 4" to 5" groups at 25yrds from a rest. And I get all the rounds on the paper with a 10" slow fire pistol target at 50yrds using a rest.
I developed the load for my M&P, its a real bonus that it works well in all my 9mms.
I have also tried titegroup, Bullseye & w-231.
I had simular results with the Titgroup (at 3.6 gr.) but I was unable to find any more TG so I had to find another powder.
I tried the bullseye but I had terrible results (not all of the rounds would hit paper @ 25yrds) and I had simular (good) results with the 231, It worked well in my M&P but not in my 213.
Needless to say Unique is my "new" favorite 9mm powder!!!
YMMV
Cheers!