I personally have not seen the score to variations but i do perform the 2nd Scherzo.
The scherzo has no real technical difficulties, biggest challenge i had was simply learning the notes and bringing the piece to tempo. Also about half the scherzo actually is just repeats (only towards the end does the repeated section have octaves added).
But for listening to the Variations i would wager a guess they would be much much more challenging technically, as well as musically.