I seem to be caught between two IDEs: Eclipse and IntelliJ. I abandoned Eclipse a couple of years back, partly based on wide spread recommendations from many different people, and partly because Eclipse just stopped working for me (it crashed out).
After I got started with IntelliJ I started to appreciate its merits, despite a generally clunky interface (with lots of modal windows), truly awful documentation. Many things are streamlined and only a ctrl-alt-shift-coke-bottle-touch-your-nose away.
However, over time, using IntelliJ got slower and slower and slower. It also started running the Tapestry test suite horrifically slowly: 40 minutes and up (it should be about five). It would often go away, even when memory wasn't tight. Indexing? Checking Repositories? Computing primes? No way to tell.
Meanwhile, Eclipse has been moving forward, with Eclipse Galileo being a Cocoa (not a Carbon) application. Critical plugins such as M2Eclipse have gotten nice, and the Clojure plugin is mostly better than the IntelliJ one (though both are very early).
For a while I was using IntelliJ when teaching Tapestry (as part of the VMWare image I use when training) ... and I got a lot of resistance. People were much happier with Eclipse on the last couple of go-rounds, and I'm sticking with it.
Overall, I'm feeling that most of what I've grown used to in IntelliJ is present in Eclipse, just handled a bit differently. The Clojure plugins are a wash; IntelliJ has the edge on the Git plugin. I think Subversion inside Eclipse is actually better.
I've even cranked up NetBeans but didn't find anything there compelling enough to switch.
It seems like all my major tools (Firefox, Firebug, Eclipse, IntelliJ) are in the habit of growing too complex, and doing too much stuff in the background that I don't care about. All those intentions in IntelliJ that you have to turn off (for performance reasons), and all those extra plugins for Eclipse that you need to not download in the first place ... they're all getting in my way.
I think a lot of this falls into the general category of accidental complexity ... to address the limitations of the Java programming language, all this extra stuff is coming into play: tools and wizards and plugins and indexes and whatnot. I find it pretty pleasant to work with Clojure instead, where the accidental complexity of Java is managed and isolated and the IDE doesn't feel the need to be overly ambitious. That's the Clojure concept right there ... grow the language to your needs, rather than building up tools. I think that's the Tapestry ethic as well.