However, Unity's icon for virtual workspaces is perhaps too easy to overlook or work with. GNOME 3's panel for multiple workspaces on the right of the overview is much more efficient, at least until you open more than four or five workspaces at the same time.
At right angles to GNOME 3's dashboard is another menu across the top with items for open windows and applications, with sub-items that appear as large icons on the desktop and can be filtered by a variety of views or by a search window -- both of which are easy to miss on the far right of the desktop.
Unity, on the other hand, opens its application menu from its launcher (and, rather confusingly, refers to the resulting view as the dash). Unity's dash is filterable by categories, and includes a search field that is much easier to find than GNOME 3's.
However, Unity's sub-menus do have the annoying habit of displaying only a single line of items plus a link announcing how many items are not displayed -- even if there is only one. While shrinking icons to fit the space is obviously not a solution if dozens of other items exist, I can't help wondering whether an exception couldn't be made when only a few other items are available.
For that matter, you might question whether the change from drop-down menus is worth the effort by the developers or the trouble that users must take to familiarize themselves with it. In the efforts to avoid the menus overlaying too much of the screen, both GNOME 3 and Unity have created alternatives that cover the screen far more thoroughly than any drop-down menu. The result is easier to read for the visually challenged, but otherwise might be said to exchange one set of problems for its exact equivalent.
The same might also be said for the handling of windows, especially in GNOME 3. By default, neither interface allows resizing of windows beyond switching between their default size and maximizing them. Moreover, both use hot spots on the edges of their desktops to minimize or maximize, or tile windows. But GNOME 3 takes the extra step of eliminating title bar buttons to minimize or maximize buttons, forcing users to rely on the hot spots. Like the change in the menus, these changes seem to enforce an orthodoxy and limit user choice for no clear benefit.
Each, too, improves immeasurably when you learn the keyboard shortcuts. Working with the mouse, many users might risk repetitive stress with either. Consequently, part of your choice of the new GNOME interfaces might depend on your willingness to memorize a dozen or so shortcuts.
Then, too, the answer depends on how you work. For instance, if you work from the menu, then Unity has the more polished design. However, if you take advantage of virtual workspaces and habitually work with more than half a dozen windows open, then you may prefer GNOME 3.
Some, of course, will simply reject both Unity and GNOME 3, and either hope for a fork of GNOME 2 or look at KDE, Xfce, or one of the other alternatives.
However, if the choice is only between the new GNOME interfaces, I consider Unity to have a slight edge overall. Unity has improved more than I would have thought possible when it was released as Ubuntu Netbook six months ago. It even seems to be developing notifications that are both colloquial and helpful. It is still rough in places, but, at its best, Unity positions items more visibly than GNOME 3, and leaves an impression of well-thought simplicity that contrasts favorably with GNOME 3's sense of needless complication.
The differences are slight, and probably will change as each new interface matures. But, for now, I recommend trying Unity first, and giving both a chance before looking for other alternatives. For all their innovations, they are still GNOME shells, and long-time GNOME users might be more comfortable with either than with looking elsewhere.
ALSO SEE: GNOME vs. KDE: The Latest Round