We stayed here with our 2 children over Thanksgiving '04 and were completely satified. We recommend this hotel highly.
We had 2 adjoining rooms which were huge. I followed the advice given in a prior review and requested rooms in the "older section" of the hotel, I urge you to do the same.
Our rooms (these you could call apartments) overlooked the front of the hotel, main avenue and Schonbrunn Castle's grounds, but was not in the least bit noisy.
The hotel staff was always helpful and courteous.
The breakfast was more than adequate and better than in most.
The subway station and tram lines are mere yards away, so access to all city sites is excellent.
We'd stay there again.

We recently stayed at the Parkhotel Schonbrunn in Vienna, Austria which is located just across the street from the Schonbrunn Palace. When we arrived, we were disappointed to discover they had given us rooms in the "newer" section, which is really just a glorified motel/hotel type of accommodation. When we asked for the older rooms, they gave us the choice of some absolutely beautiful rooms in the main hotel. Do not get one on the fifth or "renovated" floor as they are just modern, ordinary rooms. We were on the third floor and had lovely rooms with old world charm. The rooms were huge with twin beds and a full bathroom. It was nice to have a tub as so many European accommodations are just with a shower. The rooms were big enough for a sitting area as well with turn of the century furniture. The restaurant to the hotel is quite good and not overly expensive for Vienna prices. The breakfast was served in what appeared to be a ballroom, was buffet style and very large, however also very crowded. This hotel seems to be a favourite among the bus tour crowd, so there were very many people either lined up or already eating their breakfasts when we went there at 8:00am. I would recommend it for a unique experience in a Vienna stay. It is out of the city, in the suburbs, really, but if you plan on going to Schonbrunn, it is very convenient. There is a parking garage next door, which is not run by the hotel and the cost is 19 euros for 24 hours.