When I play the Appassionata myself, I feel that the last movement should indeed be played fast.
Upon hearing other interpretations of the last movement taken at slower speeds, the last movement ceases to be a terrifying storm of anger and passion and becomes pretty dull and empty.
The name "Appassionata", apparently taken with this last movement in mind, does not quite seem to fit the slow, pedestrian pace interpretations that seem to be all too common nowadays.
However, this is just my own opinion. I respect the interpretations and choices of others - when I play, however, I choose not to listen to them, and only to myself, as to how the music should be played.
My tempo I am not sure of the metronome count, but it is above 150. If anyone wants, I can find my clock speed for this piece... I'm performing it as part of a 70 minute recital later this month.