It depends what you want. I can tell from living in Sheffield for 18 years that if you want to go see the big artists then it will take you a good part of 30 minutes to get from the accomodation which is a few minutes down the road from me to get the Sheffield Arena. Probably 15 minutes to get into the city centre to get to the Carling/O2/whatever its called Academy. The Leadmill and Plug are good places to go but since the Academy opened that's been getting bigger names plus that venue now has competition from the new Academy in Leeds. The problem with getting around Sheffield is the public transport which is crap, its never on time, timetables what timetables. I know public transport isn't perfect anywhere but in Sheffield it gets ridiculous sometimes.
When going to open days I used the Midlands transport to travel around Birmingham and on my way home my train went past Warwick. It was really good compared to Sheffield so for mainstream needs Warwick and Sheffield I reckon are the same, simply because Sheffield's buses are so poor. Hope that helps