Very interesting, Kyle--I just got back my Cary 2002 Monday, which I had sent in for a similar noise problem in the right channel. The world being the way it is, it didn't make the noise for them, but I had them do the Jensen oil cap upgrade, and they moved something else inside the unit from one place to another (you might rightly guess that I'm a bit of a low-tech guy...they said they wanted to move some doo-dads, and I said, sure), and seem to have checked it out pretty well. (Very nice folks, by the way.) So far, no noise that I can hear. If it comes back, I'm going to replace the 6922s, at least.
I do like the preamp quite well. I'm using it with an ARC VT 100 MK III and Vandersteen 3a sigs. Most people seem to think I'm crazy, but I think the Vandersteens can be a little TOO revealing of problems with source material, and I like the way the Cary makes everything more warm and friendly. I may lose a bit of detail compared to, say, an ARC pre-amp I have, but I'm generally a happier camper. (I'm going to be trying some other speakers as well, too, though.) As for tube-rolling, I've done that with a couple of other units, and I think it tends to send me into tech overload, though I do like some Amperex bugle boys that I have in my ARC LS-15 (very nicely modified by GNSC, by the way). I'm not sure the 2002 really needs it; it's pretty warmed up and tubey out of the box.
Good luck.