Can you say a bit more about that? I have some 10.8.x machines that I was going to upgrade to 10.9.x in order to fix some VPN problems that I am having with that. What's up with Mavericks and VPN? (Links, commentary etc..)
The issue was vpn behind nat wasn't working as expected, copying raccoon over from 10.8 server fixed the issue (not ideal but it took all of 5 mins).