Got my m1330 about a month ago with the T8100 and Geforce 8400 gs.
1) I got some CPU whine but it really doesn't bother me. Haven't even contacted support about it, although it might be a good thing for future reference :-)
2) Quality was the first thing that hit me when I lifted it out of the box. It's amazing.
3) Updated from A08 to A09 as soon as I got it, very easy to do and hasn't had any BIOS related problems at all (I think, see below).
4) The DVD drive doesn't produce any more sound than any other slot-in, and apart from the non-disturbing "suck in" noise it does during start up, it's all quiet when it's empty.
The problems that I do have is that my computer freezes frequently when I put it to sleep. I'm not sure if this is a Vista (got Swedish Vista, so not running SP1 which supposedly should fix "sleep problems") issue, a
Dell issue or a BIOS issue. Also, the sound doesn't go automagically to my tv when I plugin the HDMI cable which is quite annoying but easily fixable by choosing HDMI as sound output within whichever media player I'm running.