Well when I am playing it on paper I do sometimes make a mistake, or I want to remove some markers, and it's always a mess to do it.
I't true, it's easier to write on paper then with a d-pad, but I prefer the electronic form because you have contless puzzles to play and it's easy to remove markes and mistakes that would leave a trace on paper, adding more confusion.
I like the clean and neat look of the DS version, didn't try this one out yet.But I'm looking forward to it because I can understand the menus....