[WorldMaker]

1) no chrome-like tab groups

I like Tree Style Tabs and I've heard good things about Sidebery.

2) "save file" is greyed out when you download a file, requires an extra click

This makes me feel old. I remember back when this was added and some of why. (Used to be bad malware that would try to auto-download stuff back in the dialup eras where you couldn't afford to download stuff you didn't mean to download.) It's less useful today and been a while since some of those worst malware programs like that have existed or been seen as much in the wild. But even knowing it is mostly theater at this point I still have this "comfort" in the added safety of that "extra click". (And I have never liked Chrome's download anything and everything automatically by default approach.)

4) still feels like it's playing catchup to chrome

The other perspective is: Chrome maybe needs to stop running so far out ahead of all the standards work. Now more than ever with such a huge percentage of the web audience, Chrome should maybe take some responsibility and slow down for the sake of better web standards. As a web developer I know that I still take seriously "if it doesn't work yet in Firefox it is too soon to safely depend on it", but I'm an old (as established above).

[sfink]

I wouldn't describe running as Chrome running so far ahead. Some of it is ahead, and some of it is off to the side, into some swamps and sinkholes that are not a good idea to go into.

Or to switch the metaphor slightly, Chrome is like a ship saying "hey, our hull is strong enough to go bump into that iceberg over there! I bet there are people who would love to get onto it. Let's give it a try!"

[I am a Mozilla employee, and biased.]

I'm not actually opposed to getting some of that functionality, but not until there is some kind of believable restricted-access story that makes it very clear what the user is agreeing to. Permission prompts that train us to ignore them are not that thing. Wording that only talks about the benefits of allowing things are not that either. I haven't seen anything particularly serious in this direction. (It's a hard problem. Users wildly underestimate probability of abuse and harm, especially when it makes total sense for a specific person but not for the other hundred million.)