Ah, fair enough. So I suppose git's staging area has the additional benefit that you can stage some things and then shut your computer down and the staging will be there when you come back.
I have no idea whether tortoisehg remembers the state of what you've selected in its 'interactive commit' GUI, because I've only ever made those decisions when committing. Given I've been using it almost daily for about six years on a community project (i.e. not just linear commits by a single dev who doesn't need to care about anyone else), I think this is also evidence that a persistent staging area isn't super important.
I have no idea whether tortoisehg remembers the state of what you've selected in its 'interactive commit' GUI, because I've only ever made those decisions when committing. Given I've been using it almost daily for about six years on a community project (i.e. not just linear commits by a single dev who doesn't need to care about anyone else), I think this is also evidence that a persistent staging area isn't super important.