I would say, pay attention to your gut. Do you really think you'd be happier at Durham? If you have real reasons to think so, then perhaps that will be better. That being said, if you got an offer, they certainly think you would fit in.
I only know the experience of my daughter at Cam - it is extremely stressful and demanding, but the rewards (intellectual and social) are uniquely great. We are astonished at how much she has grown.
But it isn't for everyone. When my daughter started at Cam, there was a young lady in physics and she dropped out quickly and went the Manchester to study English. That was right for her. Trust your feelings, but test them.