Here is an interesting link to a blog from someone who has decided to spend two weeks trying to work entirely without Windows, using only Ubuntu 11.10 (Oreiric Ocelot) with the Unity desktop. From my perspective, it is not a pleasant read...
Source Seeker: Ubuntu instead of Windows 7
The summary is that she found a few things to like, which appear to me to be only things which are Linux-"standard" such as LibreOffice Writer, general functionality of browsers, watching Hulu and the like, and a LOT of frustration, disappointment, irritation and general problems, every one of which appear to me to be Ubuntu/Unity specific. An external monitor on the laptop isn't recognized on reboot (I have seen this with Ubuntu, and I never have this kind of problem with any other Linux distribution), mouse/touchpad click problems (actually she say only "mouse", but the description sounds like touchpad), one of my favorites WHY HAVE THE WINDOW CONTROLS BEEN MOVED TO THE LEFT SIDE and the Unity Launcher is permanenty fixed on the left side of the display, and finally why is window management so tedious under Unity. Sigh.
I have said since the first release of Unity that I didn't understand the theory behind it, I didn't like using it, but I hoped that Ubuntu "knew better" than me and most other experienced Linux users. Over the ensuing year or so, I have seen no evidence that this is the case. On the contrary, I am seeing more and more posts from people who have tried moving from Windows to Ubuntu and ended up confused and disappointed. I have made a few efforts to show Unity to friends who currently use Windows, and I have never gotten a positive reaction - not once. I hoped that Ubuntu had something up their sleeve, some OEM or some other kind of deal who had signed on to start offering a significant number and variety of systems with Ubuntu/Unity preloaded. That has also not happened.
I'm afraid that time is running out for Ubuntu and Unity. Yes, they have made significant improvements in 11.10, but those make it work better/faster/more reliably. If your concept sucks, making it work more smoothly or reliably doesn't help win over new users, because the concept itself still sucks! I'm starting to fear that we are approaching the point where Ubuntu is doing more harm that good - where they are driving away potential users, and providing ammunition to those who would point at Linux desktop systems as difficult, confusing, and generally unusable.
I still hope that I am wrong, though. I hope.