Personally, even I don't like to use any case for my phone, but just to be over-protective, and if I get a case which looks stylish & compact, I'd use it.
It might be a downgrade for the people who actually use S-Pen and its functionality to get their job done. Of course S7 has a smaller screen, but I feel like 5.1" is not that bad. So I guess it won't make much of a difference IMO.