hi there, me and the other 'arf went there on our motorbikes last year. Stayed for 3 days. We stayed in a best western which we booked on line, 4 star i think and very reasonable. Its very nice, and with some fantastic buildings and views on both sides of the river, buda and pest.
The area round castle hill is excellent.
The underground is cheap and primitive, but we used taxis when we werent on the bikes. Much of the old centre is walkable and in the evening there is lots happening, at a pavement table restaurant we were near a classical music concert performance taking place in the church square round the corner - certainly added atmosphere