I will add a little bit about blind virtuosic play of the piece. I found that there are several modes of blind fast play in the course of learning. They differ in the way as the car gears differ. One may play blindly and fast but being at the lower gear, the finger mode. You feel speed and bang your fingers away, but nothing happens, quite discouraging. Then one day you are able to shift to a higher gear, where the hand motions are slightly different altogether, the attention focus leaves the fingers and goes up to hand, wrist and arm, the phrase mode. And later on you learn into, say, the piece mode (I am not there yet), when you mostly control large motions of the body, such as ones of the shoulders and thinks about music connections, general flow. Like climbing up a hierarchy.
At the highest gear level, actually, you must brake yourself with speed. The Appassionata is written, as I perceive it, with a special intention to hide seething emotions under the hood. That is why one should not abuse it with loudness and speed. The listener may only guess himself that a fire is under the surface. A calm behavior of a world karate champion, who is able of much but demonstrates little. It is the more challenging task for the sonata, then getting to the speed. Thus, one should learn to the tempo and beyond it to be able to descend a step and make that impression. Hardly artificial cheating will do, one should be able to play the thing faster really (a real power under the surface, not a bluff and imitation) to play it in the proper way…