To give a personal, subjective point of view of why I switched from hg to git:
- hg was horribly slow compared to git;
- I love the branchs model used in git to let several persons work on different parts of the same project, and I could never find a satisfactory equivalent using hg idiomatisms.
It is true that hg has a far better UI in general, but Magit fixes this problem for me.
The UI thing is more than superficial though. Yes, the command line is horribly inconsistent (and that can be fixed with Magit), but the real issue is that if you want to do anything non-trivial you have to understand how git works - what the object model is, how refs work etc.
I used mercurial successfully, quite heavily, and I couldn't tell you much about how it's implemented.
To add more praises about Magit: I would really love to use other DVCS, especially Fossil because it has built-in issue tracker and Wiki and all, but to be unable to use Magit with Fossil is a bigger drawback for me to make a switch.
At this point, I can basically do most of Git commands in Magit with just muscle memory; say, stage everything in the tree, commit amend, reset author and dates, then force push (I know) to remote I would just press with evil-magit: <SPC>gsSc-Racp-fpy (<SPC>gs for invoking Magit, S to stage everything, c to enter commit mode, -R set the reset author flag, a amend commit, p enter push mode, -f set the force flag, p push to origin, y confirm force push)
It may sounds complicated, but the Magit UI is discoverable, and once you're used to it you can do anything without even looking at the UI...
