For those in the UK, I ordered black M-80s (personally prefer them to the white) from Amazon.com on January 7th, and to my surprise they arrived this morning (16th), despite the estimate being the 23rd. I paid just under £130 after tax/import fees (which Amazon charge at point of sale), compared to the £159.50 'Computers Unlimited' are currently charging on Amazon.co.uk.
Having read/watched every review on the Internet, I took the plunge and ordered them without listening to them beforehand, due to the fact nowhere in the UK stocks them.
First impressions are very good. I've found they clamp pretty tight, and I don't have a particularly big head! But they're comfortable enough, I had them on for around three hours before my ears started to ache a bit.
The sound quality is superb out of the box straight from my iPod Nano using Apple Lossless. I am far from being an expert, so won't attempt to use jargon I don't fully understand, but I've listened to a few albums (UB40, Chili Peppers, Gorillaz, Ryan Adams, Mike Oldfield) and they seem to handle everything pretty well. But yeah, there's plenty of detailed reviews out there from people far more qualified than myself!
But if you're ordering from the UK, Amazon.com isn't a bad way to go.