Of particular note; the numeric row on the physical keyboard. The three row keyboard with shared letter/number row that seem popular really do suck when one needs to hit numbers regularily (an "alt" key every time I need a number gets tired quickly).

For lack of access to a Nokia N950, it's tempting to compare the hardware and see if the upgrade justifies the switching costs (bah.. not yet.. still not ready to accept Android as my personal lord and savior).