Good value! We also like Premier Inns - not quite as cheap, but their beds are among the most comfortable I have ever slept in (including a Vi-Spring mattress at The George in Rye) They may not have the charm of a country house hotel or a boutique hotel in town, but with one digit less in the price I know I am getting a clean room, a good shower, a comfy bed, a hairdryer and (mostly) parking for the car.
Your trip to London nanej sound perfect! We once stayed at the one further along the South Bank so that we could go the The Globe and it was ideal. Breakfast was in the pub next door overlooking the Thames and it was lovely not to have to struggle back to Euston for the last train home We met DD and SisIL at Tate Modern the next day for lunch and felt we made the most of the night away.