Hi Ryan,
I actually took the plunge and upgraded my production server to 5.6 not too long after it was released and after the main packages I intended to run have been updated to support 5.6.
As far as stability goes, I have no complains as yet (touching the biggest block of wood I can lay my hands on !!!), by that I mean it has not crashed on me, it has not mangled any of my files and I have not lost root or user access to it as others have.
I am, however, being plagued by the ongoing problems with PPTP. I too rely heavily on PPTP to support various clients and have found (even after applying Charlie's updated packages) that out going PPTP connections are still problematic, though better than plain vanilla 5.6. Without the updated packages, I was having lots of problems connecting to 90+% of my clients. With the updated packages, I can connect but traffic stops after a short while although still connected. I have to disconnect and then reconnect before I can continue working. Sometimes it lasts for a few minutes, sometimes less than 1.
I've been quite lucky in that things have been fairly quite with clients and I have not had to do any major remote support since I upgraded to 5.6. I keep hoping that a final fix will be made soon. If not, I will probably have to move back to 5.1.2 as well.
Kelvin