Just to keep this topic going..
I have a demo D-Link Response Point system here at home to have a play with.
My initial thoughts are very good indeed. Under 15 mins from unpacking the boxes and I have a working PBX with 2 phones registered and a trunk connected to my trixbox system home here.
Configuration and setup is dead simple - people will argue all day whether that's a good thing or not but it's obvious a huge amount of work has been put into making this system as simple as possible.
Dislikes? So far my only complaint is having to dial 9 to get out - dialplans should be created to this isn't necessary. In the old analogue PBX days days they were necessary - now they're not.
Voice recognition is very cool. Press the RP button on the phone and say a users name and it calls their extension.
More to come later when I've had a bit more of a play..
It was disappointing however to see that Remote Branch Offices were not supported i.e. all extensions had to be on the same subnet. I was involved in configuring a system that successfully traversed NAT at both ends and enabled the Remote Extensions to be part of a Hunt Group just as though they were in the same office as the other extensions. It's disappointing to see that this wasn't supported.