Can anyone explain why would someone use GitLab vs Enterprise Github?
I could see us using GitHub further down the road after we get some best practices in place and start using Git more, but for the time being GitLab is an excellent way to test the waters, especially since the GitHub Windows and Mac apps will work with an arbitrary 'origin' URL.
I'd imagine the main reason to go with GitLab is that it's free. GitHub Enterprise costs more than Stash (although it offers more).
I know that there is some payed service that isn't self hosted.
You might trust US companies, but after Snowden many people don't trust the US anymore (industry espionage). And there is no reason if you aren't a one man shop to not host such things yourself.