I've been in Gnome 3 desktop environment for a little while now, now moved to Fedora 16 and newer Gnome that came with it and things are getting better. See [update] comments below.
- Looks pretty
- Quickly position 2 windows to share the screen in half - like that
- Improvements to switching between applications/desktops
- I can no longer have programs sat in the panel, I used to like having system monitor amongst others there
- No 'system tray'. What is that area called in Gnome? Anyway... an example of why that is a nuisance to me: no quick access to Banshee to skip music/quickly rate a track while working on something else [update: move mouse to bottom right, 'systray' pops up - I do find this can get in the way sometimes when I'm trying to select something in that area of the screen]
- Everything seems to be hidden away several clicks deeper in menus
- Can be hard to find programs if you don't know what they are called
- Good looks require hardware 3d graphics acceleration
- To be usable you have to learn some key-strokes, to start with I found myself getting annoyed with mouse navigation
- No minimise button on windows, minor niggle really as the improved switching between open programs helps
- As much as CSS/JS may be easy enough to customise, it certainly isn't a couple of clicks to add a shortcut to an application into the panel as it was in Gnome 3, I'm not even sure if it's possible to create shortcuts to applications I have installed locally to my user so have to launch from CLI
So it looks good, but in order to get the shininess much has been sacrificed in usability in my opinion. Maybe I'm just too used to the old way of doing things but so far I'm not too fond of Gnome 3. It just feels like Gnome 3 was built from the ground up for the new generation of tablet/touch screen devices with big Fisher Price style icons.