A great place to experience theatre, good acoustic...

A great place to experience theatre, good acoustics, friendly staff and a really nice ambiance.
The seating can be a bit cramped and access along the rows not easy, but the plus side is you can be really close to the stage and even at the rear of the stalls you are closer than in many west end top price seats.
There is a restaurant and bars for pre-theatre food and drinks in subterranean surroundings (the old vaults), while these places have a great atmosphere they are totally impractical for disabled guests as all involve steps with no lifts - yes I know the age and style of the building is a limitation but I would think at least one of the areas would be accessible?