From my experience,
git svn is troublesome but sometimes you have no choice.
Using only svn or only git is fine. I used to love svn and switched over to git primarily due to it’s user-friendly structure and interfaces. Unfortunately using git and svn together with a git repository pushing to a subversion trunk branch or some similar setup can get tricky.
I’m not an expert with git svn but I do have some experience with it mainly due to hosting plugins on the WordPress plugins directory and repository.