Really friendly reception staff and personal trainers, which is a very rare thing in London gyms.
Being under the concourse of Liverpool Street Station, it's quite small gym and slightly cramped men's changing room. One one occasion the men had to use the womens changing room, and it was very spaceous and roughly 50% bigger than the mens changing room. Given that about 75% of members are men this seems odd.
Good selection of free weights and machines (including really good cable machine, only problem is that the rubber cover of two of the grips on the fixed pullup bars is faulty, which bites into your hands a bit).
Good vaule for money if you go off-peak. I wouldn't ever consider going at peak times, ie between 12 noon and 1pm, and again (according to other gym users who say they tried peak times) after 5pm. This gym is way too small to be a pleasant experience at peak times. Once I finished my workout around 12.15pm and the gym and changing room was rapidly becoming very busy, too crowded for my liking. It's ok at off-peak times though.