[Serusers] Production experience request - uptime, stability?

I'm considering implementing SER in a production environment where at least 80 people are using SIP phones to register to and dial through SER to FXO gateways to analog lines. These 80 people will be on the phone for the full work day. I was wondering if anyone could give me any first-hand accounts of using SER in production, and if possible, could you tell me how many calls you are making in a day, how many concurrent users, how are you backing up (I assume just the ser.cfg file and MySQL database is sufficient), what is the uptime, stability, and reliability like? I've got a test box up, but I would like to hear from others using it before I roll it out into my production environment. Thanks in advance! -- Dana