It's a really good place to live actually. I do pine for London sometimes, but that's partly because my best mates live there. There are a vast number of pubs, I think about 6 within 10 minutes walk of my house. Public transport is ok, trams and buses, but tbh I live 10 minutes walk from where I work so don't really use them.
It is hilly, but cycling is pretty popular and most of it is manageable... You'd probably want to avoid Crookes and Walkley though. Crookes is student-land anyway.
Nether edge is really nice, it's about 4 miles out from the centre and is sort of leafy suburb, stone house type stuff. It is also on a hill, but not as bad as some others. Prices for property there were quite high last time I checked though. The borders between Nether Edge and Highfield are nice enough, close to Abbeydale road (main road into town), lots of shops and stuff. Elements of grimness, but nothing exceptional.
I live in the Sharrowvale bit of Neepsend now, new flats and student halls. It's actually pretty nice round here, mostly it's also very convenient for my workshop. There's a lot to be said for the older 'character' properties in Sheffield, but there's also a lot to be said for flats with insulation and double glazing... They're quite reasonably priced... iirc £90-120k.
There's plenty of interesting crustiness around, lots of people with workshops, lock-ups etc. Industry might have been damaged, but there are still loads of people with smaller businesses left - joiners, saw-makers, steel fab etc.