I've been using this extension for, I don't know, how many years. At least 5, but probably more, and I love it.
There are a couple of things that this extension is missing on Firefox, though.
1. Shortcuts. Chrome's version has the ability to set activation hotkeys and some more. That's not the case for Firefox. As one of the many users who prefer keyboard-driven workflow, this feature is really missing. In fact, this is the only extension (out of 10) that forces me to use a mouse. I hope this feature will be added.
2. Auto dark mode. I can manually set the dark theme, but It would be nice if the extension could follow the system theme.
Other than that, the extension is really must-have.

works well enough for checking emails, but is really lacking a keyboard shortcut to open the preview window without having to click on it

I really like being able to right click on tabs and email them, but the notification function keeps disabling itself. If/when I notice that, I have to go in and wake the hamster running the process.

This is a good addons but they add all the gmail when you login I hope it will add sync system when we login there it will add out previous gmail. Thank you

Feels a little bloated and Dark Mode is behind a pay wall.

This extension is awesome!! Wish there was one for Outlook;

The version for Google Chrome has many more features and options :-(

Only complaint is having to move my mouse just a little bit when mass-deleting e-mails. Can't just spam click without it opening the next one.

It don't adjust to the overflow menu when open an email. Please fix it.

Please add customizable shortcuts for popular actions. Thank you.

Just what I was looking for. I have only one quibble, so far. I wanted to activate the voice input, I know it says Beta, but I thought, give it a try. The thing is, in the options area/Voice Input, I can't get it to activate. The check box won't accept an entry. I checked my Win 10 settings for the mic, and everything was fine. So I'm puzzled as to why it doesn't work. Anyway, I like this add-on, especially since I have a couple of accounts for different people etc, and it works very well.

Thank you so much for the last Firefox update !! We know this addon was working for a long time only if we used the "Add account and keep login status" and it required extra permission to use gmail account.

Now it's working perfectly just as the same as in Chrome without needing to add the account manually, I returned to FF again just because of this :)

Only problem I noticed:

The move To Folder function not working currently.

Im getting "error: Error getting labels backup method" error.

Love this extension, but just upgraded to Firefox 60.5 ESR and it does not function correctly using this version of Firefox. Will this issue be corrected?

Appears to work just fine with the stable version of Firefox 65.