As is customary with any Ubuntu release, I downloaded the recently released 11.04 and took it for a spin.
The installation started off well. I liked the fact that it got started on the install and then asked you the configuration questions, minimizing the overall install time. And it looked like the install was galloping along. Then it bogged down, and got slower and slower. Made a coffee. Drank the coffee. Install going nowhere fast. Checked the Royal wedding pictures, played a few ZX spectrum games. Install going nowhere fast. Updated a slew of other applications on my Solaris box. Install going nowhere fast. Finally, after over an hour, it finishes the install. That was gruesome.
After installing the guest additions for VirtualBox I got the new Unity interface. And it's not all that bad. It's not that good either, but I didn't get the horribly negative reaction to it that many have reported. In a lot of usage scenarios, I can see it working just fine.
So, what does Unity get you? Well, it works pretty well for simple task-based computing. If you just have a handful of applications that you use, and you only use one at a time, then it works great. It allows you to focus on the task at hand. It starts to struggle if you're multitasking or if you need to do a lot of different things because once you're outside the simple task metaphor it really struggles.
Is Unity radical? Not really. I've used dozens of desktop interfaces. So this one has panels on the left and top rather than placed elsewhere, but that's no big deal. The window controls have moved, but that's trivial. Seriously, there's nothing much new here.
The problems I have with Unity are really that it doesn't fit my normal working style (which tends to involve having huge numbers of applications open, often many windows of the same application). The launcher on the left only really scales up to a dozen applications or so; beyond that it becomes cumbersome. It folds up whatever's at the bottom of the list in the normal view, but expands things out (forcing the launcher to scroll) if you use the folded-up applications. And you can't clean things up by moving your applications across multiple virtual desktops - you get to see all the launcher items all the time, rather than just the ones relevant to the desktop you're on.
Dealing with multiple instances of the same application works really badly. There's no good way to organise 100 xterms, for instance. Double-click on the xterm launcher icon and they're sitting there in a 10x10 grid. But which one's which? Again, sorting them by virtual desktop doesn't really help. And right-click on the launcher icon gets you a menu, including quit - which quits all of them.
Another major change is the move of the application toolbar to the top of the screen. I hate this for two reasons: for one, it means you have to mouse all the way across the screen, and for two, it interacts really badly with a mouse focus policy of focus-follows-mouse. Fortunately, I tend not to use application menus very much.
None of the criticisms are necessarily aimed directly at Unity, of course. It's more that it has changed to a new usage paradigm, but all the rest of the desktop and all the applications haven't, and the mismatch shows pretty clearly. What would be really interesting to see would be what Unity would be like with applications designed around it, rather than with all the (legacy, for it) applications we have today.