Worked well with only 1 hiccup

My Problem

Original HD sata cable failed and decided to put a new faster drive in while adding a second HD in the optical bay.

My Fix

Just like the guide described...except I had purchased a HD with a 6gb/sec transfer rate and it gave me problems. Upon further research it appears that my late 2011 macbook pro has reliability issues with this speed of transfer. So I just used the original HD in the optical bay, maybe one day I'll put something else there but for now it'll work.

My Advice

If you are putting a second hard drive in this model macbook make sure you get a 3gb/sec HD, it'll work right the first time.