I read some of those complaints on the forums a couple weeks ago, and as far as I could tell, those who were complaining were either:

a) encountering the video and audio stuttering shortly before the upgrade, indicating the upgrade was unrelated.
b) reporting broadcasting problems that weren't the fault of their equipment at all
c) having hard drive failures completely unrelated to the upgrade (the timing was just coincidence)
d) having audio dropout problems when using the digital audio output of the tivo (which I don't use).

Now, the fact that someone you're working with personally has been having a problem, and you specifically have checked it out with him and you're sure it's none of the above, carried more weight with me than all the posts on the community forums combined. So I'm a bit worried.