I'd be willing to bet that the high-polish slide (which is not just for show--it's more resistant than matte finish to rust... yes, my K9 Elite has rust because it's matte) is also indicative of a high-polish feed ramp/throat, and possibly a more refined trigger.
Of all the Kahr's I've tried a trigger on, I like my K9 Elite the best, that's including T9's. More love is put into the K9 Elite than the rest of the whole line. The feed ramp on my barrel is high-polish even when compared with regular K9's and T9's. I'm willing to bet that slightly bit more polishing goes on in the inside of that Black Rose P380 than the rest of the line. I could be full of it. I've never gotten to handle one. They are probably rarer than my K9 Elite. I really want to see one now.
Heck, grrrrrrrrrrrrrr.......... I kind of want one now. Curses!
ZOMG! I didn't read the OP well! I thought it was a P380! GACK. How embarrassing. I would still apply the above logic to PM9 Black Rose. I just didn't know they made them!!! That's pretty neat.
At the very least the high polish is kind of nice for the smoother magazine release, which can be over sharp on Kahr's, which is also true of my K9 Elite.