IntelliJ used to look quite a bit like a Swing app. At least on OS X, going from 10 to 11 was a major visual improvement. You can tell it's not native, but it's MUCH closer than it used to be.
I don't use Linux, but IntelliJ uses native font rendering in Linux according to their blog. Give it a try.
Can you point me to where on their blog they mention they're using native font rendering?
http://stackoverflow.com/a/12976496 shows me that they aren't using native font rendering.
Hmm, I don't use Linux myself so I can't really be 100% sure. But I found the info here. Maybe they don't mean "platform rendering engine" when they say "system fonts"?
http://blog.jetbrains.com/webide/2012/10/phpstorm-webstorm-5...
When you see this on the first run, it kind of successfully undermines the argument about ridiculous attention to detail. I know that Swing is not under JetBrains' control, but Eclipse looks fine.