I have used it on both Linux and Windows since early 1.x series. The betas that are out for Linux are substandard. I have spoken with someone at ActiveState about the issues and hopefully Beta 3 will correct them. I won't get into the specifics since they may or may not be platform specific, but the Beat 1 was useless and in Beta 2 one of the major new features (revision control) didn't work, which was the most compelling reason for me to even consider it.

2.0 seems to be a big improvement as far as feature set and user interface, but I think the speed of the applicaiton has taken a hit. I am not sure how much memory and what speed processor you are using, but I would recommend at least a 800MHz machine with 128 MB if you aren't running any web servers (mail,apache, etc.), my development is mod_perl based and I have a local server for testing so my memory is requirements are higher because of that.

I have stayed with 1.2.9 for now since the majority of my work is in Linux. You can read my somewhat dated review here at the monastery as well.

Update: Changed did to didn't