A personal view is that this particular movement is most virtuosic and biased to solo of all piano concertos that i know in ligt of its mechanical demand and the proportion of the cadenza, more virtuosic than Rachmaninoff's #1, #2, and #3, Saint=Saens' #2, Prokofieff's #3; Tchaikovsky's, Liszt's #1 & #2, in sharp contrast to Schumann's (my other favorite and i performed earlier this year) and Brahms' #2.
The major difficulties associated with this particular movement is primarily due to the composer's idiosyncracies around harmony using frequent shifts and composites, in addition to its quite broad movement of both hands over the full range of keyboard, often crossed, presenting tremendous challenge to the performer.
The composer himself found his own creation immensely demanding to his surprise, and it is said that the composer found the need to practice four hours a day to master this piece.
As a concerto, however, it is not very demanding in terms of rhythm, collaboration, and tempo, though.
Therefore, if you get command of those mechanical demands especially of the cadenza, you'd be mostly in good shape performing this movement, which nevertheless requires a lot of careful and thoughtful effort.