That's hard to take, considering how long it took me to stop pressing ctrl-y for redo when I switched to intellij.

It's not just that it doesn't do what you expect, it's that what it does do is disasterous for someone who was expecting redo (because it destroys your forwards edit action tree).

IJ's mac settings are absurd. But you can change the settings to whatever you like. I've synched up my keystrokes from IntelliJ/RubyMine/AppCode and Sublime Text 2.