The Undo command works rather inadequately for me. It groups typing across cursor movements, which it shouldn't do. For example, if I type this line:
a sample text.
Then I press Home and type \verb' ' around the 'a' :
\verb'a' sample text.
Now I decide to undo the \verb thing, so I press Ctrl-Z:
a sample
As you can see a lot more is undone than just the last typing, \verb''. It might be how it was designed but it is not how Undo works in other editors. Not a big thing, but a bit annoying.