I'm running Ubuntu 12.04 at work and it's pretty impressive. The user experience takes many cues from the Mac, but it never feels like a copy. Yesterday I took my old toshiba laptop, which was running an older version of ubuntu, and upgraded it to 12.04. Now it feels like something I can actually use.
This is a very special laptop for me, chiefly because I used it to work on threddie.com??and other important projects before getting my first mac. So it feels really nice to have it operational again. I might try coding and launching something with it, for old times' sake.
Back to Ubuntu. If you want to give linux a try, do it. Unless you really need to use some specific piece of software that runs only on windows or mac os, Ubuntu 12 is a really polished and friendly OS. I highly recommend it.