I am a bit obsessive about making my revision notes aesthetically pleasing.
It usually involves fine-liners or biros in rainbow colours and black ink (not blue or weird bluey-black biro).
I recently found out that it wasn't all for nothing.
Over the holidays, I borrowed a book on mind-mapping from the library.
In this book, I read that 'pretty' notes actually increase memory.
The colour and neat handwriting not only make your notes easy to read, they also make you spend more time reading and processing the information as your brain likes to look at pretty things.
So overall you're absorbing more of the information!
So to sum it all up:
pretty notes = more useful