Maybe I am living in another world. I consider myself a power user. I have usually around 15 apps open, many of them multiple instances and I used to have the Cairo Dock installed to manage my desktop and windows.
My first reaction to Unity (on 11.04) was rejection. I switched to Gnome2 less than 5 minutes after first trying.
But last week I was working on a remastered Ubuntu 11.10 to promote our new products, and I decided to leave Unity as the GUI for the time being. And guess what? I actually liked it. I decided to install it on my main system too. And it is still there.
All comments here about having to search apps in the dash prompt just indicate ignorance. You only have to do that once, then you can add the apps icon to the launcher.
You can now launch multiple instances of already open apps like you do with, say, the Cairo Dock.
Alt-Tab works as expected, with the nice added feature of a nested view of windows belonging to the same app.
There are still some rough edges and the fact that the dock cannot be moved from the first monitors left screen edge is extremely annoying.
But it has a lot of potential and deserves a little more appreciation than the bashing by people here who obviously haven't tried Unity, but nevertheless have string opinions about it.