Well, having built a VM yesterday I installed 11.04 on a real machine - my test laptop.
I could have run the upgrade tool from 10.10 to 11.04 but instead chose to build a second install side by side. Installation was pretty smooth - no hiccups to speak of, and this time Ubuntu came up with Unity as the default window manager.
What can I say, it's a window manager. On first look it's a bit too Ookygoo-ish with big chunky icons for the big three Libre Office apps and Firefox. Now it's arguable that 90% of people don't need much more than that out of the box, but I feel it simplifies things too much.
Now I've used gnome for years and know where the apps live in the menu system, ie I have certain expectations of the window manager, and as we all know change can be hard. It would be interesting to see how the UX experiences of experienced Ubuntu users and users new to Ubuntu compared.
Let us say I'm reserving judgement ...