Trying out hg for the first time - "hg init; echo hello>world; hg commit" prints a "nothing changed" and I have no clue how to get it to commit my file! Whereas git says 'use "git add <file>..."', and, as that's already required for starting tracking a file in both hg and git, it's not entirely unreasonable that you'll need to do "add" upon modifications too.

So in hg you have to explicitly think about file tracking and get changes for free, whereas in git you have to explicitly think about changes and get tracking for free. Obviously I'm biased, but I think "I need to tell git what changes I want committed" is a nicer model than "I need to tell hg when it should realize a file has started existing"; the former is pretty uniformly annoying, whereas I imagine the latter quite often results in adding a file, forgetting to "hg add" it, and making a bunch of commits with changes in other files as the new file is intergrated, but never actually committing the new file itself, with zero warnings.

Git's staging/index, messy as it is (and with some utterly horrible naming), is extremely powerful, and I wouldn't accept any VCS without a sane simple equivalent. Extremely do not like that "hg commit -i", adding some parts manually, and deciding that I actually need to do something else before committing, loses all the interactive deciding I've done (maybe there's a way around that, but --help and "man hg" have zero useful info on interactive mode, not even what all the different (single-char..) actions are; granted, I don't really understand "git add -i" much either, and just use a GUI when necessary). In my git workflow I basically always have some changes that I won't want to commit in the next commit.