Version Control

So, as most of you probably know, I like distributed version control, and my weapon of choice in this arena is Monotone. I wanted to ask everyone what version control system they prefer to use, why they use it, and what work flows they have, especially with multi-person projects.

I am especially interested in the following:

1. How you manage many divergent branches and changes from multiple sources with many involved
2. What you think distinguishes your version control system (the key difference that keeps you using the system) compared to other modern VCSs
3. How long you have been using the system and how large your repository is