Heh, unfortunately I don't.
The easiest way to tell is to see how easy it is to remove the barrel. Perhaps take a picture of your slide assembly of how soon you're able to remove the barrel, and that'll give you an idea of how loose your bushing is. I was able to remove my barrel at nearly a 45* angle (okay, I might be exaggerating), but it had a ton of play. I think one thing is that you will definitely see an improvement no matter what, and if you don't mind spending money for every inch of performance, get the bushing.