Overall I do have to agree with Yukon Trooper, M$ has done a dayumed nice job with the whole 360 and RRoD problem(s).
While I personally don't own one, my sis/bro in law do.
The first time they called into M$ they had to do a few tests and resetting of the software. Which seemed to fix the problem for a week or two.
Once it started back up, they called again and were given the details and info on sending in their unit.
It was about 2 or 3 weeks turnaround for a replacement/repair.
I am unsure which was done for them, never had the chance to check it before they sent it in or when it got back.
The replacement/repaired unit has worked flawlessly since though.

So while you do have a bit of turnover time, it is not too bad IMO all things considered.

Again, agree with Yukon Trooper, kudos to M$.