Which Beyond Voice package are you evaluating?
I have one client that cut over to Beyond Voice 3 back in May2010. So far there has been only one failure in CBEY's network, and their support seems to be on top of things when I have called them. Since my client connection to the phone system is a PRI ISDN, I have no experience with the IAD that offers POTS lines. They did provide much documentation for the client's phone person, and it seemed to cover most of the items needed for cut over, etc. in both the voice and data areas. During cut over we had some minor problems with the LEC in the number porting department, but it did get resolved finally, except for a foreign exchange line that got screwed up because they mis-communicated what CBEY was going to send as digits for the FX number as DID. They fixed that the following day after I had the assisting CBEY tech do some call traces to see where it stopped, and they told us what digits they were sending. The BV3 uses three bonded DS1s for service, and voice takes priority in this case. The PRI is a full 23B+D. They are doing a good job in that area, because I have only once been able to detect any voice degradation during a call. Otherwise it has been performing extremely well from my point of view during the times I have been there and used the service. As far as the data and Internet goes, I have not had any complaints from anybody, but I need to check the latency and other things to make sure that side is performing properly. This client only uses the handoff from the IAD. They have their own firewall/routers. So they don't use any of the freebees that CBEY offers, like email and VoiceMail.
Hope this helps!
....JIM....