Social life/night life of Bath vs Birmingham?

Hi,
I will be studying biochemistry, and I have recently firmed Bath - however I am now having second thoughts about my decision, mainly due to the overall student life/social life. I can still change my decision for the next week or so.

I have been to see both universities, and for whatever reason felt better about bath (may have something to do with the weather being good on that day).

My question is how does the social life of these two compare? Especially bath, is it lacking as it is a smaller city?
I enjoy going out for drinks and parties etc. but never dance so i guess i wouldn't be huge on clubs.

Thanks for any advice/input