I am nowhere near as cynical as most of my fellow commentators. I do believe that the "Metro" interface was a genuine attempt to rethink the UI from the ground up, with no legacy constraints.

Having used Window 8, I think it's a cracker on a portable touch-screen device. It wipes the floor with Android and iOS, which suddenly look so last-century (my opinion, of course).

BUT, but, but..... you will guess what I'm going to say as it's been said so many times before...... "Metro" / "Modern" / Whatever is a FAILURE on large screens (e.g. the 24" screen on my desktop) because all the elements of the UI are just too big to scan easily by eye. It's madness to use up a full 24" screen (or even 3/4 of one) just to read one email. It's just too big, with too much dazzling white space.

And another (oft said) thing: switching between Metro and Desktop is a major mental speed bump. Yes, you can cope with it well enough, but it really jars and spoils the smooth feel of the new UI.

I wish, how I wish, Microsoft had had the balls to do two things differently:

1/ Allow desktop users to switch off the Metro part of the UI entirely (not with a 3rd party kludge)

2/ Leave desktop mode OUT altogether from W8 RT.

The latter seems only to be in there so they can offer MS Office to RT users. What a terrible kludge! Without any trace of desktop mode, W8 RT would be the very embodiment of Microsoft's vision for their new UI.

Yes, I know there would be a delay making a "Metro-ised" version of Office, but it's a risk I absolutely would have taken. FWIW, I suspect the desktop mode will disappear from RT at the next release, when MS have had chance to develop a Metro-ised Office.

Those are two criticisms that have been made thousands of times already. And I believe they are absolutely valid. But those aside, if you stay inside the "Modern" part of the UI, and use it on portable-sized touch screens, I absolutely love W8 and now my Android devices look and feel seriously drab, klunky and old-fashioned.