I've stayed at this hotel during a business trip and it offers most of what a business traveller needs. Location is great, literally on top of the Stuttgart Hauptbahnhof. You can purchase a ticket for 3,5 Euros from Airport and you will arrive here in about 20mins via train. The hotel rate includes an- all you can use- free public transport ticket for every day you stay at the hotel. Although the hotel is in the main train station, I have not experienced any train noise. There are plenty of decent cafes and restaurants around for a quick bite as well.
However, please do not expect a stylish hotel. I found the rooms decent but a little gloomy and dated. Not too small, but not too large either. The bed was low and soft. The pillows were very thin and large square shape but otherwise clean, lcd tv, a desk to work on, small minibar. The non-smoking room was a real non-smoking room.
A couple of negatives: Noisy air-condition and very expensive internet. 9 Euros for 5 hours of internet is a little expensive.
The staff I've dealt with were extremely helpful and friendly.
I have not taken breakfast at the hotel.
To sum up, if you are looking for a central location to sleep for a few nights and use as a base; this is a good hotel in a good location. I would not recommend this place to couples or families on a holiday, maybe looking for that little extra.