Great review, very well done!
One minor nitpick, though: The C3000 is not the first Z with a directional keypad. The vertical units (5000, 5500, and 5600) all have this keypad. The one on the C3000 does look nicer.
Of course you were really only talking about the clamshell units, anyway. Your review makes me wish I had the "fun" money to spend on a new Z to replace my aging (but still excellent) 5500.