The call group feature seems to be very powerful for call distribution using tags but I was unable to get this to provide any call quality. In my particular scenario I was using tags and simultaneous ring. I was able to point the main telephone number to an IVR or simply assign the main number directly to a phone with better call quality but ultimately call groups are what the customer needed.
I was told there is a known bug for call groups and would like to know if this problem has been resolved so that I may attempt to deploy a group of MC phones in above mentioned scenario.