Itunes is great for personal use stuff -- if its less-than-robust error correction misses a problem/causes a skip, you'll (eventually) catch it and can fix it on your copy.
Itunes, is not, otoh, a good idea for ripping live cds to be traded. In this situation, you would never hear the problem and the recipient of the trade could have sent out a bunch of now-flawed disks (and/or bittorrented the flawed show) before the error was found.
MP4/ACC/MP3 -- I use an Iaudio m3, which supports flac, ogg and mp3, but does not (yet?) support mp4 or acc. My wife uses an ipod, which doesn't support ogg, but does support mp3. In order to share between platforms, I've been ripping everything as 256k mp3s, do you think I should be ripping @ a higher bandwidth to maintain sound quality (256k mp3s sound surprisingly nice to me), or do you think that the acc/mp4/ogg advantages exist mainly at lower bitrates?