i use unique mostly because I can use it for my other loads (there are decent .32 acp, .357, and .380 loads).
I haven't noticed it being any more dirty than winchester white box or remington/umc. Some people say it is. I may try universal when I run out of this lot, just because I hear it compared favorably.
My 1911 LOVES 185gn FMJ over 7.5 gns of Unique. Im not sure why, but my XD eats 230s better.