Personally I got the "doomsday" offer which had a huge discount for IntelliJ IDEA Ultimate. And in my opinion, this IDE is worth every penny and I'm sad that I've stuck with Eclipse when I was working on Java projects.
I found that it had feature parity with Eclipse for the most part, but there was enough missing that I went back to Eclipse. Time to donate!
I also use Eclipse for C/C++ but I run a separate instance for C/C++ so using IntelliJ wasn't an issue.
For my workflow IntelliJ didn't seem to add anything, but it did take away one or two small things.
A minor thing, sure, and there are ways around it, but the Eclipse Scala IDE found all classes. I have gripes about Eclipse as well, but nothing is perfect.
To be back on topic, I had a very similar experience after using Eclipse for several years. A co-worker introduced me to IntelliJ in 2005, and I have not regretted the decision since. IntelliJ is a fantastic IDE, particularly for Java.