Now I am comfortable to say I tried GNOME and Unity. I have used each for about a month now when I intended to use them only for a week or so. That says something about the redesigns. I liked it. But that is too simple a statement about something like GNOME, isn’t it!
You can switch between the GNOME 3.x shell and Unity easily, if you wanted to. There are too many common aspects to wage a war between them – modern compositing window managers, keyboard-oriented launchers, dashboard with shortcuts to applications, dock on the left side, panel on the top, smooth effects. Since the underlying framework is still GNOME’s you will see some more similarities in the applications. There are also some striking similarities with my OS X, especially in the way the dock handles open applications and UI controls.
The bigger difference is in the technology of the interfaces – Mutter and Compiz. Although they too normalize to similar behaviour in the end. The biggest difference is in Ubuntu’s aim of using it across all Ubuntu products – TVs, mobiles apart from desktops, laptops and netbooks. This might make Unity more modular in future than the shell. Other differences, IMHO, are minor and can be worked around. As an end user they are cousins – same age, same face, just different clothes.
I intended to use GNOME for only a week, but continued to use it because it intrigued me. I will be lying if I say that I did not like the smooth effects. They definitely have their impact. Even my family members, who are non-techie end users, enjoyed the new desktop paradigms. I tried to fit it into my workflow. However, now I am back with my Xfce and Xmonad setups. In spite of being cleaner, the new GNOME Shell and Unity paradigms do not get out of the way enough! For me, using desktop environments and window managers should not be about them at all. Xfce can do that, XMonad is great at that. GNOME Shell and Unity might get there, but today using them is still about them, maybe because they are in works. I have a similar rant about KDE 4.x version.
I will look forward to their development and how this desktop space evolves. I will definitely recommend new users to try these new desktop interfaces. This might pull in more users who have been skeptic about Linux, either as too technical to use, or too old-school. For people like me, Linux already works.