"Centre of Brighton" covers a large(ish) area but I'd expect you to get better than that (a mate of mine lives in Woodingdean and that's the sort of speed he gets).
Mine's been running slow all day today, could Windows 10 be the culprit ?
http://www.expertreviews.co.uk/software/1403670/windows-10-downloads-to-slow-down-the-entire-internet