The major drive was Chrome's poor handling of dozens of open tabs, which was slowing down my Macbook to a crawl (8GB Core i7 2012 13" Retina on Yosemite) way too often. "The great suspender" extension helped somewhat, but it felt like a lot of manual work for something I believe the browser should handle much more smartly on its own.
Firefox is better in this respect, with sane native behavior like not trying to restore 100+ tabs in parallel upon restart, and extensions like UnloadTab that automatically suspend tabs after some timeout.
However, I'm about to switch back to Chrome :
- I only have 3-4 active tabs in FF at the moment, but as I type this I can feel noticeable lag, and firefox+WindowServer fighting for CPU.
- Embedded video is jerky and looks like it's 10-12fps no matter what the site. Going full screen fixes it, but still..
- No FF extension I've found integrates Google Translate as seamlessly as Chrome does.
I'm not looking forward to handling dozens of tabs in Chrome again, but its baseline performance for everything else is noticeably better for me.