I ended up getting a Grandstream 4104 but am having some issues with it - did you have any problems with the provisioning? Dialing in doesn't seem to be an issue, dialing out is the issue - not reliable. When I dial an outside number with the correct outbound rule A) it takes upto 10 seconds before it starts to ring and B) sometimes the call never makes it to the grandstream, but no errors is shown in the server activity window. So, basically I make a call - it works, hang up, hit redial and it doesn't.
Any suggestions?