My iBook G4's drive has a noisy loading mechanism, and is about as loud as a typical desktop CD-ROM drive when spinning at full speed. For a laptop, it's a bit ridiculous.
One annoying thing is that it spins much faster than it needs to when playing back audio CDs. DVDs aren't so bad though.
There are programs for controlling CD speed for Windows and GNU/Linux. Any equivalents in Mac land? IMO, there should be a system preference for optical drive performance that would keep both the noise-averse and speed freaks happy.