i have had a 128gb M4 for over a year now and never had a single problem with it. i backup to a HDD (not raid) weekly. games installed on a SSD load almost instantly. you may not see any boost in FPS, but for me the time saved on loading screens is huge.
one downside, you will never be able to read a load screen "tip" or "hint" again...
How are you backing up? What SW? If you ever had to restore, how would you go about it? Would you have to reload the OS, etc? How does that work in the terms of product keys? Would you have to buy the OS again or will it let you re-use it on the same drives? Not sure how that all works, but trying to save the hassle the best I can in case of a giant HW failure.