Oshyan - no doubt you are right. I'm having the same experience with MusicMatch, which I bought in 1998 and for at least two years have kept on my system out of sentimentality more than anything else. It's become very bloated and likes to have all sorts of things run at startup even if, as is the case, I don't open the app from one month to the next. Actually, you've given me the impetus to ditch it! I'm uninstalling as soon as I post this missive.
If I was more proactive, I'd ditch a lot of other resource hogging detritus as well, but at the moment everything is running sweetly. As you might gather, given that I am posting on this site, I love to mess with my computer and its settings. Thus, annoying as iTunes is, buggering about with it and other settings is therapeutic for me! Don't get me wrong, though, if iTunes really did start to noticeably degrade the performance of my computer it'd be gone in a heartbeat. Perhaps I should rip it out of my system and see if there is a difference? Well, that'll have to wait for me to get off my rump and burn the DRM'd tracks to CD. Might just do it, eventually...
FWIW, I've had no troubles with iTunes DRM method while I have had several with Puretracks (they use WMA). What a nightmare - I paid for a handfull of tracks and most of them are unplayable because the licenses for them have been corrupted, or weren't migrated to a new harddrive properly, etc. Contacting the vendor to have the license re-issued, even with receipts, is like driving a spike into your own forehead. Now THAT'S a PIA (I guess that should be PIF...)! Actually, that's what prompted me to try iTunes in the first place.