I have been using SQL Developer since its early days, namely because it runs natively on the Mac. Despite this fact, it has proven to be a formidable IDE to work with, allowing me to do 95% of what I need to quickly and easily, all without having to spark up a Windows VM.
In this month's Oracle Magazine, David Peake, the APEX Product Manager, writes about how to use SQL Developer to assist in debugging APEX applications. By instrumenting your processes in APEX with just a couple lines of code, you can trap and then debug your PL/SQL from APEX in SQL Developer's debugger.
While you'll need DBA privileges to get this to work, it's something that's not intended for production environments, so I don't envision that to be much of an issue in most cases.