Even if the bug wasn't in our code, it was really helpful to see what's going on inside, helped us figure out why something didn't work a lot of time. Making false assumptions, passing stuff in a different format than the system expects etc.

We all, always worked with a decompiler in eclipse, just because it really did make life so much easier sometimes. And well, of course, sometimes there really was a bug in the stack, and finding a workaround is much easier when you know what's going on.