I have a clone of git://git.gnome.org/evolution which I "git pull" couple times a day, usually in the morning. It's a writeable checkout, but I do not expect it making any difference.

The thing is that if I "git pull" with gitk-1.7.10.4-1.fc17.noarch then it takes too long, sometimes close to a minute, sometimes I'm not patient enough and I Ctrl+C it, as it seems stuck. If I downgrade to git-1.7.10.1-1.fc17.x86_64, then the "git pull" is significantly faster, it takes about 15 seconds.