I haven't played with Unity much, but I'm running F17 and I have to say, as much as I despised Gnome 3 when I first encountered it, Gnome Shell extensions[1] have taken it from an unusable pile of excrement to a legitimate improvement on Gnome 2. Gnome Shell, for all of its design faux pas, is built on an incredibly modifiable foundation that allows you to reconfigure just about everything. Moreover, these modifications are dead simple to share (easier than adding an extension to Chrome).
Sure, it's worse than just getting the damned thing right in the first place, but it's much better to get things wrong and make them easy to fix, as Gnome has done, than get them wrong and make them unfixable, as Microsoft has. For that reason, I resent the comparison of Metro to Gnome Shell, although I get where it comes from. There's nothing wrong with Gnome that can't be fixed with some some js and CSS. Your UI is essentially a web app that you can modify arbitrarily, which is an incredibly powerful idea. Metro may have some themes, but there'll likely be no way to fix its underlying issues.
Can you give some examples of Gnome extensions you find useful? I tried perusing the list a few times but nothing really jumped out at me as a huge improvement.
It seems it's not really a popular opinion, but I also like Gnome Shell a fair bit. It just gets out of the way for the most part.
Sure. I started off by installing cairo-dock (pkg, not ext), a nice OSX-style autohiding dock (tweaks req'd). This allowed me to install Remove Activities Button[1] and Applications Menu[2], which combined to replace the rather useless and annoying Activities menu with a standard Gnome2-style applications menu, and get rid of the ugly dash that was stuck to the left of my screen, hogging real estate. This had the sanity-preserving side-effect of removing the stupid hot corner to Overview that I would accidentally trip every other time I tried to hit the back button in the browser. It can still be accessed with the Tux/Windows key. I also installed Force Quit[3], which puts a little 'x' next to the Applications menu. Click it, then click any misbehaving window to kill -9 all procs associated with it. Haven't had to use it, but it seems handy.
Next, I installed Brightness Control[4], as the fn+arrow keys don't work worth a damn, and Advanced Volume Mixer[5], which replaces the standard volume bar with a separate bar for each app. I installed Remove Accessibility[6], just to de-clutter, and All-in-One Places[7], to give me some handy shortcuts.
Quit Button[8] replaces the username "status" menu with the familiar options from Gnome2, and Settings Center[9] gives me quick and easy access to a variety of settings menus. Finally, Frippery Move Clock[10] puts the clock over in the top-right corner, where it belongs. I'll probably look into installing some workspace-related extensions as I become more comfortable with the system.
The combined result of these small changes is a system that I find far more friendly and usable. As I said above, the only thing I find wrong with Gnome3 is the defaults. Gnome Shell is incredibly extensible, and absolutely gorgeous. It now works for me like a cross between Gnome2 and OSX, with some handy extra features thrown in. Some of these changes are fairly major, while others are tiny tweaks, but I love how simple and easy they are to experiment and play with. Most changes are instant, and enabling/disabling extensions simply involves flipping a toggle switch on the extensions web page. I've only been running F17 for a week, so I'm sure I'll discover more changes to make the GUI just right.
Sure, it's worse than just getting the damned thing right in the first place, but it's much better to get things wrong and make them easy to fix, as Gnome has done, than get them wrong and make them unfixable, as Microsoft has. For that reason, I resent the comparison of Metro to Gnome Shell, although I get where it comes from. There's nothing wrong with Gnome that can't be fixed with some some js and CSS. Your UI is essentially a web app that you can modify arbitrarily, which is an incredibly powerful idea. Metro may have some themes, but there'll likely be no way to fix its underlying issues.
[1]https://extensions.gnome.org