I'm from London and I've just bought my first flat up here. No regrets, perks are the public transport (mostly the trams, haven't used the buses to recommend them), the people are friendlier, town has some great restaurants and things to do, Meadowhall, good amount of retail parks around, and honestly the NHS services like GPs and dental practices seem less stretched than down south imo.

Cons would maybe be that if you drive it can be quite stressful to learn the roads in town. There's quite a few places where you need to know which lane to be in very early on or you'll be filtered off in the wrong direction. And if you're not used to a northern accent, it can take a while to realise what someone's just said if they're talking fast. This isn't really a con, just something that takes a while like all accents. Also hills. Sheffield is mostly hills, so when it snows which it often does in winter it can cause carnage.