Google Toolbar NO IF... Rated 5 out of 5 stars
I'm using Google Toolbar on 3 PCs now and had never to patch a file besides about:config.
My FF 13.0.1 even works with "extensions.checkCompatibility.13.0 = false" (no ".1" needed). OK, I prematurely added one with "...14.0=false" but that shouldn't be it, should it?
On one PC though I had to uninstall and reinstall the Google Toolbar (I'm using V7.1.20110512W and recommend using this one; you can "google" for it ;-).