The 'parallel climb and descent' at the very end is the best part of the this sonata. One advise I can give you (and this makes the song a whole lot better) is to emphasize on the 1st finger (left hand) and on the 5th finger (right hand) on both the climb and the descent -- so it sounds like this:
da, da, da, DA! -- da, da, da, DA! -- da, da, da, DA! -- da, da, da, DA! -
and then down the descent -- DA!, da ,da , da -- DA!, da ,da , da -- DA!, da ,da , da
all the way down,, so you don't sound like your playing a wave,, the 3 movement of moonlight is a powerful song,, and should be played that way . I always hear pianist play it soft,, so no feeling,, its sad to hear someone play a 15 min sonata and end it with a spark. Check out Walter Klein's version of the 3rd movement,, he demonstrates the power (if interested, email me, I have the .mp3)-- so you dont just hear it,, you feel it...
its all timing,, and practice -- I know how frustrating it can be when you play the whole song fast,, and the ending slow.
hope I helped.
-as