I've gone in to try out the web beta a couple of times (I'm especially keen to try out the new search functionality, and I like that the web version will now show PDFs inline). However, just viewing a note (without making any changes to it) changes the note "last updated" timestamp. I always sort my notes by last updated descending, so this bug means I can't afford to use the beta web version at all for the time being. If I do, I'm going to have a pile of notes which I've just viewed at the top of my list, upsetting my organisation.
I'm fine with the "updated" time stamp changing if I edit a note, but it's problematic if I am just viewing a note.
I remember there used to be a similar bug in the Windows client version a few years ago, but it's long since fixed.