University of Leeds vs University of Sussex

I received offers for International relations from Leeds, International developments from Sussex, so happy!
Leeds(International relations) and Sussex(International developments) is looking like my firm. I'm so stuck between the two as they both offer great things.

As a student i work hard but i'm also very sociable and student life is an important factor for me. Leeds has one of the best student unions in the country which would really help me adapt and settle in to student life. However, it is 93%student satisfaction for International relations ranked 24th in International relations compared to Sussex which is 85% student satisfaction and ranked 1st for International developments.

However, Leeds is a Russell group university and did improve compared to Sussex which is not Russell group and decreased but is still higher than Leeds in the league tables.

Sussex is right by Brighton which i love, the campus is small which is great as it has the communal feel but is a negative as everyone knows everyone.
However, Sussex is not a Russell Group so is not as heavily funded for student union events and research as much as Leeds. However, Leeds offers free gym membership and has better eye candy. These little details just show how torn i am between the two.
I would appreciate your thoughts/advice if you're in the same predicament as me and especially if you're current/previous students at either universities. All replies are welcomed!