I've been using Intellij professionally for about 4 years, and find it to be the best predictor of Java programming among it, Eclipse, and Netbeans.
Recently, my job has required me to use ClearCase for version control, and with the lack of support CC in Intellij 6, I moved to Eclipse. Having used Eclipse exclusively for 6 months, I have come to appreciate Intellij's UI all the more, but I also have a new appreciation for some of the plugins that are available for Eclipse. In this case, the ClearCase plugin.
The Eclipse CC plugin offers a clear and distinct visual feedback on the state of files (checked out, hijacked, etc.), as well as nearly identical features to the ClearCase Navigator.
In the other hand, having used Intellij 7 Milestone 2 for a few days, it seems that the CC capability was written in as an afterthought. I cannot figure out what, if any, visual cues there are, and how to perform simple operations, such as searching for checkouts. I have spent a good amount of time going through the help system, and cannot find the information that I need.
I want to be able to use Intellij, but this seeming lack of CC support is making it increasingly difficult for us software developers to make a business case for the associated cost, given that Eclipse is free.