Also happy with my move to Firefox, it surpassed my expectations. Two (small) pain points have been:

- customizing userChrome.css .. It was a bit time consuming to figure out first (I wanted to remove the top bar and use vertical tabs). Happy to be able to do it, but it's not exactly user-friendly.

- Rejection of Windows local certificates store that requires fiddling with a setting to enable. If my certificate store is compromised Firefox is not going to save me. I don't recommend it over Chrome at work since we have one of these for a local server and I'd rather not generate support tickets.

Both of these are not part of Firefox Sync and require manual handling on each PC.