Shortcuts are absurd and some thought in defiance of common sense (in fact it is designed for tablets). On PCs even touchscreen thing has little interest since the office work requires anyway the mandatory presence of a keyboard and a mouse strain significantly less than using the touchscreen.
This bastard OS on PCs is only for tablets that promote area and definitely wants to be a transition OS, a test. The next will be crucial for Microsoft, but it brings that fundamentally frivolous things based on entertainment - also quite poor (Modern UI interface and tiles, poverty blind, bugs apps to no end, Besides the Modern UI interface connection problems often when the office always connects well and Microsoft will move towards a model in which Apple is pathetic) Who needs a real PC to work properly, Windows 7 should do it for at least three more years.
As for performance, it may be slightly faster and stable than Windows 7, but it does not have large defects at this level with a good machine it is noticeable only very little.
We should have Windows 7 to the release of Vista, I bet Windows 9 should have been the real Windows 8 brings real new things.
