I've been a member of gll in Hackney for a few years and have always been impressed with their services. When I moved to Waltham forest, this was the first gym that I tried out to be my new local and regular one.
While the pool and track looked pretty good, the gym was really dissapointing. It is tiny, with no windows and lots of broken machines. The changing rooms were frankly terrifying! Dank with flickering lights. I've never got dressed so quickly!
If you want to join a gym in E17 DONT go here! Peter May, which is about a mile away and also in the gll group is so much better