Where did I "find it", jb? It not only found me, it then proceded – in about 10 secs. (as Rob noted) – without so much as a fare thee well, to install itself. BOOM!
If the Mozilla Foundation wasn't behind this little puppy, I would have been, well . . . . just moderately out-of-sorts.
I can't say I sense any significant difference in its operation(s).They haven't heard-about/fixed-up the anomaly katscan and I were discussing the other day, viz. "runaway" scroll bars/buttons.