Thanks for this thread, it helps me too. I totally forgot about the iTunes upgrade that would occur with Mavericks and I should've spent more time thinking about it. My problem is that iTunes 11 is really not useable to me and I previously reverted (in Mountain Lion) to iTunes 10.7. Additionally, all my music (376GB) is on a network drive that I also access with Sonos. Well, I'm not convinced that iTunes 11 won't muck with the files there, screwing up my Sonos access as well (iTunes 10.7 is very well behaved and is a known quantity). This whole thing about iTunes becoming an integral part of OS X (***!!) seems to be just a brazen money grab. I actually agreed to the iTunes license terms on my iMac and then saw that it was iTunes 11 (as it started to reorganize my music library) so I force quit it but don't want to go through the elaborate rollback, go forward, rollback, etc., process that looks like would be necessary to get future updates (including to OS X) via the App store <sigh>.
In my opinion, although I know there are also some welcome security fixes in 10.9, Apple is clearly using the "free" approach to try to move users towards making "more" (music, apps, etc.) recurring type purchases from Apple to keep their cash registers ringing. For now, I'll continue using Mavericks but I won't use iTunes 11... and I've already chosen to no longer buy Mac computers (I have 4 Windows machines, an iMac and a Macbook Pro) as they've made them basically non-modifiable by the DIY'er (so no home upgrades to hard drives, for example)... except, I think, to add memory. I like being able to do what I can in the area of maintaining my own stuff [although typically not until after maintenance warranties expire ;-)]. I do *not* like the feeling that I've been getting in my little Mac world that I must do everything Apple's way, which includes sending them my cash, even for things I could easily do myself.
One question I have is this: if I should roll back to Mountain Lion, will that OS continue to be updated (security fixes, general bug fixes, improvements, etc.)? I have a feeling it will not. It seems to me that to keep your computer running right in the long term (as far as operating system updates), there is no choice but to continually upgrade to the "latest" OS X version. Hmm, that makes me wonder when the obvious will happen, i.e., when will they go to, say OS X 10.10 (or 10.X), and do something like remove support for the older 256MB video hardware (as in my iMac from late 2007)? The goal being, of course, to force new hardware purchases. Seems to me it's just a matter of time but, then, perhaps I'm just becoming cynical in my old age <wink>.
Again, thanks everyone for the comments in this thread, I appreciate them very much.