Low Tech (sorta!) solution:

I agree, it would be very cool to have advanced 'marking' features as a reminder for why you marked a song: However.. I do think it would be pretty challenging (and dangerous) to mark the song quickly and concisely whilst driving i.e. having to look at the remote for the sequence of buttons to press to mark a song 're-rip', 'normalize' 'leading silence', etc - better to try and minimize the remote use while driving, if possible.. especially in the early stages of empeg usage, which is when an mp3 collection is really tested and found to contain issues - and when you're fumbling with the options even when parked! (speaking of myself, of course)

Solution:

Goto Radio Shack, and get yourself a digital mini-recorder.. I have it my door-pouch. A song comes on that needs attention, I reach over - grab it - and press one button.. record the issue - Done.

The bonus to this is that I can then use that recorded info at my computer, and clean the files there - and THEN resync with the Rio. Makes it easier, faster, and much more detailed to leave youself a voice message, than trying to 'pigeon hole' each error into predefined categories.. sometimes bad rips transend categories.... IMHO, as always....