I have. I've used all of the git GUIs. None are as good as p4v as far as a GUI goes, and none are particularly usable by artists. Especially powerful in p4v is the timelapse view, which nothing in any git client comes close to approaching.
I recently switched to GitKraken from SourceTree. SourceTree has better features and workflow, but SourceTree performance is very VERY terrible. I'm talking 2+ minutes to wait for some operations to complete.
Not sure why GitKraken makes it so hard to add remote repositories and doesn't allow auto-push, and other niceties. But I use it for normal checkin / branch switching workflows and it's great.