What is better for Asterisk SER or OpenSER

Hi All,

I plan for a distributed asterisk system that will use SER or OpenSER as
proxy for logins. I need to pick a ser server and not sure if to pick SER (IPtel.org) or OpenSER (openser.org).
I would like to hear opinion/advice of users.

Note: I prefer that the SER server will run on Fedora.