Stayed at the Hotel Mondial in Langenfeld when travelling for work in August 2009. It's much smaller than the photos and website would make it appear, seeming to be quite a family run place.
The room I stayed in was recently renovated, and had everything you could ask for apart from a tea/coffee tray (although it is quite common for hotels not to have this in Europe). The room was spacious and included a sofa and a balcony which was pleasant for evenings when the weather was good. There is also free wireless internet.
The room was very clean. My only complaint in that department is that the duvet and pillows seemed to be quite old (although covers were brand new and spotless).
There is not much to do or see in Langenfeld, and the hotel is about a 10-15 minute walk from the shops and cafes (though these are not much to write home about), thus the 3 points for location.
Our stay was made by the staff here. They were very friendly and helpful. They spoke very good English which was an unexpected bonus as my German is very poor. Nothing was too much trouble, and it was always service with a smile.
Breakfast was also good - a typical continental affair, but plenty of choice.
Overall I was pleasantly surprised by this hotel. I hadn't been expecting much based on the hotel website and other tripadvisor reviews, but I had a very pleasant stay.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC