They are designed quiet flats, (I'm staying in one) basically no loud music or parties in the flat and if you get back late then don't be drunk and loud sort of thing but can still go out. I know a couple in my flat that go to parties occasionally and it's no problem
If you did choose this option then be aware the people you are living with might not choose to go out to parties but if your fine with going with none flatmate people then it would be fine
Also you are able to do profiles at Sheffield and pick the room if it's your firm and book before a set date and can find the sort of people you would be living with so that might help