Still shoot my old stuff I purchased many years ago. Some came in a metal square tin with pressure 'pop' top, other in a cylindrical cardboard paper can. All of it is Hercules.
I have used Unique since the late 1960's and continue to find it useful and reliable in all my midrange pistol loads, mostly 44 special and magnum. And, I have always found it to be dirty. As some earlier stated, my hands look like I have been working in a coal mine after a session at the range. Regardless, I never really cared about how dirty it was, but it sure became noticable when I started shooting stainless guns.
It remains a superior powder IMO but I am having difficulty finding it as I have begun looking while my supply dwindles.
I imagine there are other, superior, powders on the market today, but I have no motivation to change unless I can't find any in the future.