The studio is very central (Soho). The layout is really cute, and well organised, relative to the small size of the place. It's not an upscale studio, but it is very good value for money. We enjoyed it!
There are some construction work outside, that will last for 2 more years (according to the London-tube website), but it's not noisy, and don't affect the comfort.
The main down side is the heat: we were there at July, and the studio can get really hot. Only 1 window can be opened, and there is a ventilator, but it's still very warm.
Another small problem is the fact that there is no place to leave the luggage in case your flight arrive early, or depart late, so you will have to go to a train station to do it (try Charing Cross, it's 9 GBP a bag).More