Ok, so there is a perfect time for me to post my experience.
Everything went fine when I shipped it out there and they sent it back around 10 days later. It was later than expected, but I didn't care.
When it came back the USB door on the front no longer had the spring working. The door just fell open and stayed. Once again, I didn't care TOO much, as I was told this was a permanent fix and I should probably expect some collateral damage along the way. Also, I should note that I paid $150 ($30 fee for estimate and then $120 for repair).
Now, come 6 months later of it working fine and I'm back to the same issue. It did exactly what it did the first time with occasionally erroring on start-up and then a restart would fix it. Now, it completely broke. It won't ever start up correctly, with the same error code. Figuring the xbox was toast, I opened it up to see what they did. I was afraid if I opened it up after they fixed it, I'd screw something up, so I never touched it.
First off, my x-clamps are gone. I don't know if this is part of the process and I'm a newb, but they were gone. Next, there were tools marks all over the inside of the case. Overall, I paid $150 to extend my 360 for 6 months.
I'm not trying to bash these guys, I'm just sharing my experience.