Having had a proper prod around with FF57... my thoughts are: RAM Usage: Amazingly, it's worse than Chrome. Regularly tops out at over 2GB [Chrome at it's worst seem to hover around 1.2-1.5]. CPU Usage: Again, FF seems to hammer the CPU a lot more than Chrome did. Sending tabs to/from a phone: Firefox are the only ones that seem to grasp you may want to send a page from your PC to your phone. Edge only want to do Phone -> PC and Chrome somehow makes it a ballache to send pages in either direction. Tab groups: I appreciate it never worked as intended, I appreciate next to no-one knew the feature existed and even fewer used it... But it was one of the few things unique to FF that i actually liked/used a lot so i'm sad it appears to have gone. Pocket integration: Sorry, but that shit should be an add-on. The UI/UX: *sigh*... I've seen worse, and firefox itself has been worse but mistakes have most certainly been made, and there are enough annoyance to make me want to find the team responsible and give them a slap.