Having worked with Idea (by Intellij) for a long long time I have to admit that I’m a big fan. They’ve managed to conjure up every single useful feature you could ask for, and excluding v. 7 & 8 their IDE is very well behaved, works fast and responsive even in big projects (the one I worked on had over 1m lines of code).
However, their personal license costs 200$, and community version has some limitations (I’ve looked at v.11) especially with running external servers and with debugging JSP’s, which made Eclipse a better choice for me at this stage (early startup stages, no extra money to spend).
I was a bit fearful of using Eclipse and the IDE did not feel intuitive at first, but having played around with it for the past couple of months now I know what to expect and can say that, while not as comfortable as Idea, it is still a valid choice.
Bottom line: choose Eclipse if you can’t afford the 200$, you’ll get used to it eventually and won’t miss Idea’s extra features that much (aside for ALT-F7, the ever so useful find-usages, which has only a slower alternative in Eclipse called Show-Hierarchy)