I stayed at Hocus Pocus Tiny Hotel in York during a work trip, mainly because it was the cheapest option available at the time. The hotel is incredibly well themed and has clearly had a lot of thought put into the design. Everything was very clean, the linen was fresh, the pillows were lovely, and the bed itself was fairly comfortable.
However, the main issue is the noise. Because it is right in the centre of York, I was woken up several times during the night by people walking past after drinking in the city. The bed was also very creaky, which added to the noise. For that reason, I probably would not recommend it for light sleepers or anyone needing a really restful night before work.
That said, if you are looking for somewhere quirky, fun and memorable for the novelty factor, it is a great place to stay. It is clean, comfortable and brilliantly themed, but you do need to be prepared for the possibility of a noisy night.