Guys, thanks for the feedback. Nice to hear cogent and clearly unbiased dialogue.
It's particularly helpful to hear that the M60 is in the same league as the Studio 60. I appreciate the comments on the B&W 602, but I have already ruled them out. The 603S3 are significantly better than the 602 (IMO), and I think that the Studio 60V3 outclass the 603S3 in almost all criteria. Just mo' money.
I'm a little hesitant to pull the trigger on the M60 and find I don't like them - it's $100 to send them back.