I am reliable informed by a good fellow who works for another Hardware Publication that, without any doubt....
Tesco Express in Haggerston is the worst tesco is the universe.
What is amazing is that it shows on every google search I do.
It had it's own Tumblr page for the rankness of it.. and Google Reviews seems to utterly agree
http://haggerston-tescos.tumblr.com/
Any offers for worse?