My netbook is a Acer Aspire One from 2008 with pretty mediocre spec (Atom 1.60ghz, 1 gb ram). It was painfully slow with Windows 7 so I decided to replace it with the latest Ubuntu 13.04 daily build. And wow, call me impressed! It's like 12.10 on steroids. Unity has matured into a very snappy and effecient experience. I was primarily a Xubuntu/Kubuntu user but this experience has won me over.
Major props to the developers! I'm looking forward to the final 13.04 release and beyond, it will be awesome.