This in general is a super hotel, particularly taking into account its location in Stuttgart and in Germany. While I have stayed there with my family once or twice, I've stayed here on business likely 30+ times. There are several things I particularly like about this hotel:
1. valet parking and luggage service;
2. a terrific, large, clean swimming pool to get in your laps along with a huge and diverse sauna facility, which is a great way to begin a day or relax and de-stress after a long day of meetings and travel;
3. the staff are pretty friendly and genuinely reach out and try to be helpful, the restaurant (particularly at the bar) has great food and drinks, the concierge is great with help (sending / receiving faxes, printing e-mails and attachments, pressing suit / shirts, arranging punctual room service breakfasts, etc.);
4. the location is extremely central and easy to reach;
5. room quality and service is very much superior to the other offerings in Stuttgart and what is typical for German hotels;
In terms of drawbacks, I'd note the following:
1. the hotel isn't terribly cheap and is not suited for the budget-conscious;
2. service can at times be slow (eg, I've been late for meetings when my valet-parked rental car was not brought out front as promised, the luggage porter didn't show up, etc.), however the hotel has generally improved and I haven't noticed this recently;
3. the main restaurant has become a French restaurant more in the mode of attempting to "educate" guests as to what fine food in the view of the chef may be as opposed to providing "comfort food" to business travelers at the end of a long day; for example, last week I was served an appetizer that mixed chocolate, duck pate, raisins, bread, and some type of berry gelatin - while this may be some folks' taste, that really didn't agree with my stomach; also, instead of being able to sit anywhere, they had only one room open with candles, white table cloths, etc., I was trying to have a meal and drinks with a couple of business partners and that just wasn't the right situation, though the valet-parking and central location made for a good place to meet; I think the hotel would be better off if they also had a normal dining option for folks not interested in expensive, exotic "french" cuisine and cuilnary experiments provided in tiny portions at exceptionally high prices. For food, try the bar - they do have caesar salads and burgers there!
4. If you're headed to the airport for an early morning flight (say, to the US), do factor in extra time as with rush hour and distance to the airport, it'll take a while to get there. That being said, the hotel is super and great for business.
All-in-all, though, I would say this is a super hotel as the service is top notch and the staff genuinely try to help. When something does go wrong (we're all human after all), they try to make it right, take whatever off the bill, whatever it takes. I emphasize, though, that all of this comes at a price...