I've been using Internet Explorer for a few days since, and can honestly say the difference is night and day!.
I only have a couple of extensions loaded into FF, but it just seems that on every new update Firefox began to get slower and slower, to the point where even disabling those extensions made no difference at all. I even created a new FF profile, zilch difference!.
For a browser which was once a "no brainer" it does appear things have became a little bloated, dare I say it even a little "buggy"

Unless FF improved considerably, I think it's unlikely I'll be going back to it anytime soon!!