>>> My Info: Win7_64, Nightly 46, 32bit, ID 20151221030239 STR: 1. Make sure you have at least 2 profiles 2. Launch Nightly with option -P 3. Try to open the 1st profile in the list Result: To make that, I have to: 1) Move mouse pointer over the small radio button (because that really looks like the only option. I may also miss and accidentally click between radio and the profile name - then nothing will happen. I don't want more extra clicks). 2) Move mouse across half of the screen to hover over "Start Nightly" button. I'm using Win7 on HiDPI, so since there's no option to make profile manager less thick, we're talking about huge dimentions. User is just forced to move mouse across the screen and I personally need 2 mouse movements to perform Step 2. Expectations: There should be a way to start Nightly with a profile without moving mouse across half of the screen towards "Start Nightly" button. So, old solution (start profile on doubleclick) and new solution ("Open" buttons) look good in this case. Except the latter was exterminated already. This was regressed between 2015-12-21 and 2015-12-22 by bug 1233032: > pushlog_url: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=4ec207bba72780009baa5638dfff046bc2a8b640&tochange=3c64b18f74a7460e529d4d28de7f9562278a420f

We can move the Start Firefox button next to the profile perhaps?

Sure, but that means to have 1 button for each profile and then the 'start nightly/firefox' button at the bottom of the window. If this is what you mean, I can submit a patch quickly.

Hmm. I guess this touches on another problem in the profile manager dialog replacement. The previous UI allowed you to select a profile and perform some actions on it, but the new replacement, even with the radio buttons, is still not quite there IMO. Here is the current UI: ================================================= About Profiles This page helps you to manage your profiles. Each profile is a separate world which contains separate history, bookmarks, settings and add-ons. * Profile: default Default Profile yes Root Directory /Users/ehsan/Library/Application Support/Firefox/Profiles/mf0c19uk.trunk [Show in Finder] Local Directory /Users/ehsan/Library/Caches/Firefox/Profiles/mf0c19uk.trunk [Show in Finder] [Rename] [Remove] * Profile: test Default Profile no Root Directory /Users/ehsan/Library/Application Support/Firefox/Profiles/0t7o6oqx.test [Show in Finder] Local Directory /Users/ehsan/Library/Caches/Firefox/Profiles/0t7o6oqx.test [Show in Finder] [Rename] [Remove] [Set as default profile] ------------------------------------------------- [Exit] [Start Nightly] ================================================= I think the way we ended up here is by extending the normal UI, but I'm not convinced that these two UIs (about:profiles and about:profiles?manage) need to be similar at all. One is intended to let you manage your profiles, and the other is intended as a quick way to select a profile to launch Firefox with. How about we replace about:profiles?manage with something like this (note that I have taken out the page title and description -- I really think we need to optimize this UI for fast selection of profiles): ================================================= default [More] [Start Nightly] test [More] [Start Nightly] ------------------------------------------------- [Exit] ================================================= Double clicking on a name, or clicking Start Nightly next to it will launch Firefox with that profile. Clicking More will expand the profile to show the full detailed profile information table, with a [Start Nightly] button appearing next to [Set as default profile]. What do you think?

The proposal in comment 3 would be a huge improvement. I'm gnashing my teeth every time I use the current UI.