Your comments

Put another way, I think of the tabs and the toolbar as being separate things, whether the toolbar is below the tabs or to the right of the tabs. I don't think of the toolbar as being part of the tab.

Yes, that is my suggestion. Lots of apps use tabs, and they've set my subconscious expectations, which are disrupted when I click on one tab and it makes the other tab effectively disappear. :-)

Thanks for the tip on the mouse wheel. Since other apps don't support it, it might be hard to remember to use it.

This would be even more useful now that the Log Graph can be used as the primary interface.

Interesting, though I don't really understand why accepting the default name should track but changing the default name shouldn't...

Perhaps only clear the check box if there is already a local branch tracking the remote branch?

And perhaps clear it regardless of whether the user has changed the default name?

Yes, I've got two remotes, 'origin' and 'fork'. I've already checked out 'origin/master' (local branch 'master') and I'm checking out 'fork/master'. The latter can't be named 'master' locally, since that already exists, but 'master-fork' would be a more useful default name than 'master-2'.