Yep. Script Debugger was almost a requirement for doing any serious AppleScript hackery. You can explore an open application's exposed objects and tell Script Debugger to paste the path to it into your current script. Way better than guessing when you need to `tell x` in order to expose its properties or whatever.

The most underrated thing to me that made it all worthwhile, though, was Remote Scripting. I think the full potential of it has yet to be realized, and hopefully JavaScript will allow some impressive future developments.