I went to York uni for a week (dropped out after a week though but that was because of a wrong course decision), one of my flatmates was there doing English Lit. and it seems as if there was LOTS of work to do. She had a very large reading list and unlike other uni's, exams you take after January in the first year DO count towards your degree, it's only the first term that doesn't.
I never visited Durham, but there is no doubt both the city's are completely beautiful. Yes, york campus is quite concrete-y but its swarming with ducks and things, and surrounds a lake. Essentially though, it's not really about how beautiful a bunch of buildings are, but how much you're going to enjoy your course.
I don't think you can loose either way going to Durham or York as both have a good reputation - although at the moment York English course is slightly more competitive to get into than Durham. I would visit them both, and look at the courses in DETAIL (look at how the course pans out for the second year and third year) and decide which one you'll be most happy at.