Well on the Read side the Crucial is faster. On the write side though the Kingston is faster.
I just picked me up a M500. I don't care a whole lot about the write part. Its just an OS drive and i don't do a whole lot of writing to it, but I'm also running on SATA II as well so i can't even get the full speed of it.
I mean overall performance the Kingston is faster. Espically if you get the 120 GB. The M500 only has like 150 write on that but the same 500 read.