The most authentic Sichuanese cuisine I've ever tasted in this country – took me back to my childhood with the very first bite.
Service is rather shoddy, slow and impatient. But if you can withstand that, you are sure to be in for a treat. Mouth-numbing flavours, layers of red chilli oil oozing at the top, you will have diners coughing all around you as the peppercorns attack their lungs as they would then to you. If you are brave enough to experience a real Sichuanese meal, then I would definitely point you toward this place.
Not the cheapest Chinese restaurant I've ever been to, but by no means can it be counted as expensive. I'd say £12-15 per person is more than adequate enough for a filling dinner. Be warned that prices are at least 20% more expensive than suggested on their website! (Ma Po Tofu is £6.80 on the website and £7.20 when I arrived to pick it up!)
There is also a hotpot restaurant to the left of the normal restaurant, which I've yet to try (as I visit another hotpot restaurant for half the price), but I imagine it would also be very good.
The place is generally bustling and clearly a known haunt of the East Asian community – which I always take to be a good sign that it serves authentic cuisine. I myself was initially introduced to it through several Asian friends.
In summary: fantastic food, improvable service, decent prices and a definite place to visit if you ever wondered what a volcano feels like in your mouth!