I think Unique runs well pushing 230's full-throttle in 45 ACP; and 125's in 357 Magnum - and that's it. Otherwise, Unique has not impressed me - and I've used it for decades.
I don't use HS-6, never have, probably never will, unless someone gives me a pound to try out. Not that I have anything against it, or any other Hodgdon powder, just never had any reason to try them, other than H-110.
Been loading since the early 70s, and thinking on it, (now) I realize that everything I do, or want to do in handguns has always been done with Winchester, DuPont, or Hercules powders (which is how I think of them, despite label changes over time).
For light loads, and in small cases, I run Bullseye or W231. For standard loads and larger cases, Unique or one of the "dots" powders. For full house magnums, 2400 or W296.
Unique impresses me, so much so its been my only powder for the .45 Colt since the 80s. I load for .32ACP up through .45-70 in handguns, the only ones I've deliberately skipped are the 10mms and .41Mag.
IF HS-6 is what you have, or all you can get, use it. IF something else does what you want, better, use that.