Not sure how it is in the UK but they are a bit played out here in the states. Half of the white girls on campus on any given day in the spring/fall seem to be wearing them. The classic ones are infinitely better than the feminized half-loafer atrocities. They look decent on tanned legs but only if you have small calves. But personally I think for most girls they make one's feet look kind of flat and wide, even if they are not.
If you are thinking of Sperrys I would recommend the classic dark brown leather over the Sahara color as the brown holds its shape a lot better. The toe part of my Sahara ones began to sag down after a month or so of semi-frequent wear, further contributing to the platypus foot effect. Hope that was helpful!