I've been purchasing music from iTunes plus for the last few weeks. The first couple of days had some hiccups as Apple struggled to keep up with the demand, but now things are working pretty smoothly, and I'm pretty happy. I've bought more music in the past 3 weeks than I have in the past 3 months.
I don't mind using iTunes to buy music, as I don't much care about the associated album art. It's nice to flip through, and then it gets filed away in some box somewhere, only to be retrieved when I decide to rerip the album at a higher bitrate.
Speaking of bitrates, 256kbps AAC definitely sounds better than 128kbps. I was djing a party and was asked to play a few songs I did not posses. There was an internet connection so I loaded up iTunes and purchased them... in the old-skool format. To me the older tracks sound "flat" and boring compared to their high-bit-rate cousins. Could be the particular tracks, and I haven't done any proper A/B comparisons, but I think it sounds better, and that's good enough for me.