What are the main technical difficulties of Beethoven Op. 101?

[lmpianist]

In the lists of "Beethoven's piano sonatas ranked by difficulty," Op. 101 is frequently near the top, or at least in the top 8.  I'm interested to know which passages people consider to be the most technically challenging.  I realize it's highly subjective, but I'm just curious about opinions.  For example, for the Waldstein, someone might say it's the descending/glissando octaves and trilling with 1/2 while playing melody with 3/4/5.  Something in 101 is more difficult than that if it's placed higher on the list of difficulty, although maybe it's artistic difficulty.  Thanks!

[preludetr]

I haven't played op. 101 so I can't really offer any advice here, but I will say that the answer is going to be different for everyone. For me, the most difficult part of the Waldstein by far is the left-hand figurations right before the coda of the 3rd movement, where you jump from the 5th finger base notes to broken chords an octave higher.