With a short barrel such as on a handgun, I doubt the acceleration rate is going to make a whole lot of difference. You are going to have lower pressures with slower burning powders, that is about it.
I have loaded rounds with unique/H110 to about the same speed... and their wasn't really any noticeable difference. But... with slower burning powders, you are usually using more, which will increase the recoil a little. And I mean very little, with a 250 grain bullet, you aren't going to notice the difference from 6 grains of powder.
If you are getting the speed with unique, and it's accurate, why not call it good?