Bugzilla

Looking more, apparently 1738372 merely added this pref and the new behavior is part of "download improvements". Thoughts on that:

1. Inflicting this on existing profiles is a mistake. Especially since it seems like getting the old behavior requires you to know about about:config and be able to guess the pref name (this took me multiple tries). I was also unable to find the previous bug about this via search.
2. If you make this default on only for new profiles, that would solve my griping but potentially drives new users away if it breaks common workflows. I'm not aware of any other browser that does this by default, so this makes Firefox inferior for those workflows.
3. If this is driven by user studies/focus tests that show it improves usability for novices, I think you can keep the behavior but need to make fixes to the downloads panel to address it. The simplest fix would be for the panel to not steal focus, but I can imagine there being problems with that (keyboard navigation, for one).
4. If this opening and stealing focus must be kept for Reasons, the downloads panel should (if auto-opened) have a 'don't open this again' checkbox at the bottom that controls the pref, so it's immediately obvious how to make this functionality go away. For users who find it useful, they can just not check that box.

Looking more, apparently 1738372 merely added this pref and the new behavior is part of "download improvements". Thoughts on that:

1. Inflicting this on existing profiles is a mistake. Especially since it seems like getting the old behavior requires you to know about about:config and be able to guess the pref name (this took me multiple tries). I was also unable to find the previous bug about this via search.
2. If you make this default on only for new profiles, that would solve my griping but potentially drives new users away if it breaks common workflows. I'm not aware of any other browser that does this by default, so this makes Firefox inferior for those workflows.
3. If this is driven by user studies/focus tests that show it improves usability for novices, I think you can keep the behavior but need to make fixes to the downloads panel to address it. The simplest fix would be for the panel to not steal focus, but I can imagine there being problems with that (keyboard navigation, for one).
4. If this opening and stealing focus must be kept for Reasons, the downloads panel should (if auto-opened) have a 'don't open this again' checkbox at the bottom that controls the pref, so it's immediately obvious how to make this functionality go away. For users who find it useful, they can just not check that box.
5. EDIT: You could also only do this for downloads that automatically got sent to a folder - when I click 'download' on an attachment in gmail it automatically goes to my downloads folder, so it makes more sense to open the popup. If I right-click save an image and select a location manually via the system save dialog box, it makes no sense to then disrupt me by showing where it went.