It's a much better system, faster, more powerful and more flexible but not centralized and you have to understand what you are doing.
It's not like this is a feature github discovered and added. They made an easier, prettier and less powerful version of an existing feature. Certainly not a bad idea, git's command line UI is ridiculously bad UI so a super simple point and click interface was a fantastic way to grab market share and get non-command line people involved.
> the comments in a pull request are an excellent feature
Really? I mean, compared to nothing I guess it would seem great. But since I'm used to an email thread serving the same purpose those comments on github pull requests seem awful to me.
"Build software better, together."
Or, like it says on my Github mug: "Github: social coding."
Seriously, if it's just you the self hosting your git repos is much easier, cheaper, and you'll have a better handle on how git actually works. However, if you're on a team or dealing with other people, the collaborative features of Github are awesome.Once again, the correct answer is "use the right tool for the job."