I just upgraded to Ubuntu 12.04 LTS. I have upgraded each time a new one was available. The upgrade was easy like all the others before this one. I have not had a problem till now. Unity, the new user interface, did not play well with my Nvidia video card. A black screen with jumbled up colors is not a good sight after upgrading! This seems to be a common driver problem. I installed an older card I had in the computer pile and my computer came back to life. The card I installed was a Diamond Radeon HD 4670 1GB PCI Express 2.0x16 and this card worked just fine. This was not the true Linux Geek way to fix it, I should have tried to download and compile the right fix. I am not a Linux guru yet, so I just install parts that are supported.
So far I have had no problems with the OS. It reminds me of the up and coming Windows 8. I am not a fan of "apps", thus these new OS's will take some getting used to. The new "HUD" Head-up display is interesting. I may or may not try Windows 8 when it comes out. I would like to settle on one OS to run everything in the shack. I have experimented with Wine with some good luck. Maybe as I have more time I can switch over to all Linux OS.