Windows 8 as an OS is AMAZING, it is tiny, responsive, and makes my little Atom netbook with 2GB of ram feel like a real computer, while having tons more features than any apple or android tablet on the market (my netbook is a convertible tablet... and about 3 years old at that). To say that the OS sucks because of the interface for a launching platform is dumb and uninformed.
As far as Metro goes, I do not understand what people dislike about it. Yes, it is a 1st gen interface, and there are improvements to be made, but it is not all bad either. As a tablet interface it allows for multitasking... with a touch-only device... that is something that apple and android have not figured out yet. As a desktop interface you rarely ever see metro to begin with. Pin your applicaitons to the start menu, make shortcuts to the desktop, press the start button and type in the first letter or 2 of the program you are looking for. You NEVER have to troll through the old start menu, or scroll/pan through the new start screen to launch an application. File associations are super easy to set, and any time you install a new piece of software it asks you what file types you want to use with the program... it is stupid easy.
What's more; it has excellent cloud support. I constantly move between 4-5 computers all the time, and would love to have my preferences follow me. I love that I have my documents and desktop synced across my 3 most used platforms via skydrive (yay for win7 availability!). I like the new pin and picture log-in screens. I did not like metro apps to begin with, but as I have used them in the latest version I have to say that I like how they interact, and that they are simple to use and set up. I like that when I reformatted my netbook to move from the old version to the new version I already had my user picture, desktop, password, netwrok settings, and various other preferences all set up the minute I loged into the computer the first time, and that my documents were available in a few hours after they were done syncing. I like that word documents opened on skydrive's version of office on my netbook that does not have an office liscence.
What I dont like, and what nobody is talking about, is that it has the same broken voice interface as win Vista and 7. Seriously, with apple and android having superb voice commands, win8 still feels like it is in the '90s when it comes to voice integration. Voice control and dictation features are a MUST feature on devices that do not have a keybaord. And while the split keys with the #pad in the middle is brilliant, voice is simply easier for most input options. And the ironic thing is that the xBOX, which MS also owns, has relatively great voice control. It is not perfect, but it is more useful than most implementations, and I would be much more likely to use voice controls on my tablet than I would ever use them on a console.
Anywho, other than 'it is different' or 'I don't like it' what are the real things about metro that people do not like? Yes, there is a minor learning curve, but after using it for a week I really don't see what all the fuss about it is. Again, not saying it is the holy grail of interfaces, but what about it is any worse than the start menu? Personally I find that it takes less keystrokes and clicks to use than the start menu ever did, and that is an improvement in my book.