Gave my MBP a bit more of a life extension.
I had this SSD for a little while, but I knew that i didn't want to get rid of my old hard drive. And after discovering this procedure, I knew I had a new mission. 756GB sounds better than 500GB, anyway; and I knew about SSD speed sweetness.
Plus, I kinda knew that i wouldn't miss having the optical drive readily accessible in exchange for the additional space. I've also never liked the sound that the optical drive does when turning on the computer... (minor thing, i know)
Repair went well, but I did hit a roadblock that I was able to avoid with another non-ifixit tool that I already had with me. In step 11, where it says to remove the three screws that holed the opti drive, the ifixit philips screwdriver from the Pro Tech kit wouldn't fit through to reach the screw closest to the HDD. So, I had to use another similar screwdriver with a thinner/longer stem to reach it. Other than that, the procedure went swimmingly.
This is a good exercise in following instructions, and whenever there are comments from other fixers, doesn't hurt to review them as they may have some info that it's easily avoidable. For example, I almost overlooked the step about the screws to secure the HDD to the optibay cradle; that wouldn't have been good.
Not all screws are tightened the same, so pay attention to that. And have a compressed air can handy because it's certain that you'll find some dust nastiness... Goes without saying that you should be very careful while dusting inside your computer... perhaps look up some safety tips!