One has a transfer kit and the other doesn't. The i/o speeds aren't really noticeable just only a benchmark difference. Also, you will need a SATA plug and power cord. Umm, you said a couple 20 GB MMOs? like 60GB and windows which is roughly 30GB. I'd suggest upgrading to a 256 GB. It's better to not fill up an SSD or the necessary TRIM support/garbage collection won't be optimizing your SSD properly.