I have two Crucial m4's, 128gb for OS and 256gb for games. I love them. I was a bit worried about stuters and other problems when I was shopping for SSD in the spring. Was looking really hard at vertex3 drives, but after reading a ton of reviews I decided to go with the slightly slower Crucial M4 for the sake of stability and reliability.
I'm really happy with the purchase. I think going from a spinning drive to ssd was the bigest performance boost fore my machine.
I did a backup of the first beta for this patch and whenever I want to switch from the official patch to the beta, I just copy and paste the whole game folder in seconds.
I love it.