I tried the Diamond Dialer (which I hadn't tried previously) with the 20273 Kitchen, and yesterday I saw the same problem that I keep seeing with this Kitchen: The phone messed up when initiating a call (The call connected, but with no audio going out or coming in). It also totally locked up the phone when answering a call shortly afterwards after the phone had rebooted.
I have also seen this behavior with both of the iPhone dialers on this Kitchen.
In addition, this morning I had a vibrating reminder pop up that I wasn't able to clear for about a minute or so - the phone seemed locked up, but was actually just responding very slowly.
Back to N2C-5067 again, I guess.