I purchased mine yesterday and burned about 50 CDs. Today I've burned maybe 10... I've not heard any type of noise. Of those about 10 or 15 were audio CDs (MP3s converted to .wav) I had on my hard drive. Once I heard a "clunk" when I shut the CD door, but that was one time. Granted I've not used the re-write, which is where the 24x comes in but once. It seemed to work just fine, I think I dumped maybe 400 megs of info to ensure it worked.
I'm a newbie and only had the drive one day, but I'm very impressed with it... nice drive.