I just recently installed Ubuntu Feisty Fawn on my T60 again and I have to say I'm loving it. Most everything is running smoothly and I have most things I need installed. It makes me happy to see that the Sun JDK 6 is in the main repository along with Netbeans, Java DB, and Glassfish. Well, Netbeans and Java DB are sort of in the repository, you still have to download Netbeans and Java DB before you can actually install them.
Other than that my experience with Feisty has been going quite well. I have managed to set most everything set up easily and without any major problems. I even have managed to install IBM Rational without messing up my laptop. The only thing I haven't set up yet is XGL. There are a couple reasons for my delay there. First, Compiz Fusion, the merge of Beryl and Compiz is still in an alpha phase and second, I have always had problems getting the ATI driver working properly and getting all the features I need working well with Compiz. I probably will get to installing it later though, because of this video I saw.