We're preparing to move and will be leaving our current phone company's service area. My wife wanted us to keep our current phone number if possible, and we could do that with VoIP. I decided to try Broadvoice again and ordered their Unlimited World plan. To transfer our existing number, I had to retain landline service while waiting for the request for number porting to be fulfilled which took 3 weeks. That occurred on Thursday, and by Friday, we were seeing how bad VoIP can be, experiencing audio dropout, low-level, distortion, and total audio loss (dropped calls).
The device sent to me this time was a Linksys SPA2102 phone adapter with router. Unfortunately, it comes pre-configured on the same address as my existing Netgear router. It can be changed, but doing so makes the web-interface unreachable for some reason. Once that happens, the telephone has to be used to control the device and reset it, when necessary.
I have it's WAN side set to 192.168.0.4 to use my Netgear's DMZ feature. But for some reason, I still have to setup port forwarding of ports 5060-5061 for best service. This cures most of the audio loss problems, but the distortion still exists.
I also recall from last time that my service can be improved by having them change my call center. They begin service by assuming what call center is best, but changing it to another may actually result in improved service, because of net congestion peculiarities.
Having our landline service now cutoff (because that number was ported to Broadvoice), we'll live with this until the move. But we'll also be ordering real phone service from Verizon there. They offer pretty good discounts for bundled services including local, long distance, DSL and DirecTV billing (even though I already have DirecTV service setup).
The problem with DSL is that it really is slower than cable. But DSL speed is consistent, while cable internet can fluctuate. With discounts, Verizon DSL will cost an additional $18/mo.; Comcast internet will cost $45/mo. So it's probably worth it to try DSL again, if it's available.