Thank you for the lovely compliment Kevin!
KevinM perhaps a little out of my league currently.
I don’t think so! I bet that the difficulty is in line with the Songs without Words actually. I might guess that the only tricky part compared to Mendelssohn are passages with syncopation, which are more contemporary.
The main thing that makes it hard is choosing the fingerings (and which hand) for the inner voices, so even if someone is a competent score reader, this isn’t something that’s easy to read.
The other is that the piece gets easier as it goes, the first page is probably the hardest.