We've done a few SIP phone systems using Jive as the service provider. Not sure how they compare towards phone system with a local PBX but it's super easy to support remotely, we make money (reoccurring), and seems to be "reasonable" in price. But I'm guessing there is a "value" sweet spot between the number of users and a SIP system. It's also incredibly easy if the business has multiple locations.
"Just when I thought you couldn't possibly be any dumber, you go and do something like this... and totally redeem yourself!"
