I live in Sheffield and also visited Sheffield University's open day. Basically what the university and what you see online in general is they will tell you about the lets say, less nice student accom. I spoke to a student on campus and he recommended this place called Allen Court, I was told by the university student himself it's nicer than all the other places, but a bit more expensive. I have a friend whose older sister studies at Sheffield University too and she also got her accommodation there.