In depth: How much 4G data do you really need?

You're a Spotify streaming, Sky Go-ing, YouTubeing modern man or woman, so of course you want a 4G phone. But could you end up paying a fortune for data allowances you don't use, or hitting a download cap because you haven't ordered enough? If you're baffled by bandwidth or don't know how much you'll download, we can help.Who offers what?To keep things simple we'll compare SIM-only 4G plans, because phone subsidies make it really difficult to compare different providers' pay-monthly plans. Of co