It haven't crashed a lot for me. Maybe you just need to check Settings. And yes game world is very different from Oblivion and it would take some time to get used to it.
I played Oblivion the other day, after spending a month on Skyrim, and I couldn't stop smiling. When the newness of Skyrim wears off, I think I may play both games frequently. :D They both really are quality games!