I am very pleased with my stay at this hotel.
The description of the hotel amenities include FREE AIRPORT SHUTTLE but that is quite misleading because when you arrive in Frankfurt, and you ask at the Airport where to pick up the hotel shuttle bus/van there is no pick up for The Lindner Hotel. My American cell phone does not work in Europe, and I do not speak German, so it took a while to get through to the hotel desk and find a way to get to the hotel. A cab ride would have cost me about $20 - quite a bit more than FREE. So I ended up taking the train. It was only one stop away from the main airport in Frankfurt, and it only set me back a couple of Euros. The hotel was a short walk from the train station, but in the evening, it was quite dark.
Upon arrival, the staff made everything they could to make up for the mix-up on the shuttle, and explained to me that they do offer a free shuttle service to the airport, but it needs to be arranged with at least 3 days' notice. This was not made clear to me when I booked the room - so it was certainly inconvenient when I arrived at the airport and it took an hour to find a way to get to the hotel.
All in all, it was a very good experience. The room was clean and quiet, and the staff was very professional.
I would recommend it. (Just make sure you book the shuttle 3 days before you plan to arrive).