Thanks for the information, smorizio. I appreciate it.
Both 520 and M4 are head to head comparison well and you only see the different in the benchmark( google it ). In real world you can't see the different between them. You can take the one that is low price per GB.
Thanks for the input. So will I not notice a difference between the M4 and the Corsair Force Series GT, for example?
I plan to use the SSD as a boot drive for my OS and a few chosen games, by the way.