Just upgraded my Karmic box to Lucid and the process was very smooth. I wish Microsoft was able to give upgrades like this ;)
- Fast bootup.
- Less sluggish, faster response.
- New theme has nice gradation and feels nice, but the color combination is a bit of an eye-sore. Solution: Change it from System > Preferences > Appearence
- Window close, minimize, maximize buttons are on the left! Last time I checked, Ubuntu wasn't Apple's official distribution, so why is it trying to act like one? Solution: System > Preferences > Theme > Customize.
- I had the idea that Gnome was simple, however take a look at the context menu for a USB flash disk; there are 16 options displayed and many of them are grayed out as they probably don't even apply. Unavailable options should be invisible and Format and Compress can be easily put in Properties window.
- If that wasn't enough to cause confusion, the user gets two choices for the USB stick removal: Eject and Safely Remove Drive. Isn't Eject safe enough? Why not just have one option of Safely Remove Drive?
- Default search engine changed to Yahoo! even though my earlier default was Google. Easy fix is to open about:config and change browser.search.defaultenginename property to Google