Ok guys so after all of your comments I believe I found my answer on my initial question : what would be step up to MC type cartridges in price range $1200 that would be way better than 2M Black ?.
The answer is: pretty much any good brand and quality MC outperforms good quality MM.
But the real answer is the fact that in my case changing just cartridge makes little or non noticeable improvement, I need new cartridge and new phono stage, but to add problems and expenses I saddled on PASS XP 15 so now I debate of the PASS pre amps perhaps XP12 and ultimately replacing my Threshold S550e for PASS X250.8 , yes it will be expensive to do it right. Thank you all for input !