it used to be pay and its for all classes, if you want a boxing gym, i recommend going elsewhere. But for a high quality commercial gym, with good aestetics and some boxing, thai MMa classes. It's pretty good.
in the area is Gleesons , down by london bridge for boxing.
Gymbox is first class and errol is there. he is first class mate. his son trains at the gym I am at in ELtham and spot on...