We were happy with our stay at the Carlton Opera with only a few regrets. Upon our arrival, a rather surly porter took our bags up to our room via the elevator and grumbled about his $ 3.00 tip where others elsewhere had been happy with their tip. Breakfast was very good, but no other meals were offered. The room was fine except for the TV which had a weird system of set and cable-box; the remotes would not turn on the set and gave their options in Spanish only. The first night we had no TV, and the second night I found the secret--switch the TV on and off manually... Vienna itself was hot, and required much walking. The hotel was not as near to the centre of things as it was nowhere near the State Opera. All in all, though, a good experience.