TL;DR Been using Firefox as my main browser since 2005. Refused to move to Chrome when a lot of people did. As of today both my home and work machines default to Chrome. So what happened?

Earlier this year the problem started on my personal laptop. I'm based in UK and Firefox suddenly decided it will start searching in google.com rather than google.co.uk. I made sure my Google preferences say UK, my PC location is set to UK, reinstalled Firefox, nothing. IE and Chrome still search in google.co.uk. After a month of struggling I gave up and switched to Chrome.

I kept Firefox as my brain browser on my work PC. It was still searching in google.co.uk so all good. All good until like 2 weeks ago when opening a Google Hangout in Firefox started resulting in the browser taking up to 900Mb of RAM with 3 tabs opened (gmail, hangouts, website) and crashing. We use Google Apps at work so I spend a lot of time in hangouts... Again I struggled for 2 weeks and gave up. As of today Chrome is my default browser on all PCs.

What went wrong with Firefox really? I could easily blame my PC setup but I don't think so. 2 very different issues on 2 machines, yet other browsers still function normally on both of them.

I'm even considering the ridiculous probability of Google subtly screwing with Firefox users on random bases just to get them unnerved and switch to Chrome.

Is anyone else experiencing such a degradation of their Firefox experience?