Why Git over Mercurial?

To Dear +Kieran Simpson

• Efficiency: each git command is like a Swiss Army knife, with more built-in tools in one piece of device; Mercurial is like a well-equipped kitchen — it has a lot of tools that each do one simple, well-defined thing, and do it well. Do you want learn how to use only one thing, Swiss Army knife or everything in the kitchen?
• Speed: Git seems super faster to a lot impatient people.
• Complexity: There is a batch of good reasons why Git looks too complicated to someone, and there is a good book ProGit - http://progit.org/book/ demystifying all these complexity in a simple way.

Last but never the least, GitHub is so popular and dominant. It's never wrong to put your money on big elephant. History keeps repeating itself - "No One Ever Got Fired for Buying IBM."