I have had an 8500 X50 for years, just upgraded to a V1.
I went from my 8500 X50 S7 blue to my V1 3.872. I was amazed, I thought the 8500 was totally awesome and it is. But the V1 blew it away. That said, I now run the Sti-R with my V1 and still have my 8500 for a back up. I just can not part with it.