I too have the D610 and love it, with reservations about the headphone feedback that's been discussed in forums here:http://notebookforums.com/showthread...d610+headphone
Reasons I chose the D610:
1. Price (I too found it to be cheaper relative to a similarly configed M3)
2. I/O port placement. It makes no sense to me to have USB ports on the right side of the machine, towards the front (as is the case with the M3). If you don't use a mouse much this probably isn't an issue. I personally prefer the D610 port placement better.
I wrote up a review on notebookreview.com about the D610 (shameless plug):http://www.notebookreview.com/default.asp?newsID=2268
Others whom I work with have toshibas and love them. They seem like quality machines to me, but I've never used them regularly.