I like it a lot, it make git as simple as mercurial. I don't think it is hiding complexity, but the visual arrangement makes sense. The staging area becomes actually useful, and I love that you can stage (or revert) pieces of a file, which is handy when you forgot to commit one thing before moving on to the next.

I've only had to merge a branch once, and here I was completely confused on what was going end. This may be SourceTree's fault or git's fault. Maybe my lack of understanding.

I hate git, I don't understand git, I don't want to have to understand git, and I think the command line interface makes every UI error in the book. But SourceTree has made me like git.

We have a bunch of projects that are stored in a mercurial repo so I've been using Sourcetree for that as I've found MacHG pretty unusable. I think it's pretty good, not as good in my opinion (the UI, mainly) as Tower for Mac which I use for Git, but makes Mercurial easy to use for this (somewhat) hardened Git user.

Incredibly slow. I was never annoyed so much when using a software...