I always think the best way to explain my opinion on these two is to compare to genres of recent days. Let's take the 70's for comparison for instance ... Mozart would have been the "pop composer" of the day, like Abba, The Partridge Family, The Osmonds, perhaps, while Beethoven would have been the prog rock of the day. Deep Purple, Emerson Lake and Palmer, (early) Genesis, maybe. Just a thought more than an opinion. I just find Beethoven to be deeper than Mozart. Better? I don't know. I think it depends on my listening mood, but I like them both.