I noticed when trial booking flights on the Condor site that there was no cost to add on many other nearby cities, so I explored more and found out about DB's Rail & Fly. It offers free ongoing travel by rail after arriving in Frankfurt on Condor Airlines to all German cities and even some outside Germany.
Has anyone tried this Rail & Fly option and how does it work? It looks like you get unlimited rail travel (stop as you like) to the destination you chose (or maybe any direction?) for the day of arrival in Frankfurt and then the whole next day? And it's free for regional trains, which I know from experience can be very quick in Germany, or can be upgraded to ICE for 10 euros per train?
For example: Could a person train to Nuremberg the day of arrival, spend the night, then train to Cheb, Czech R (a DB train to just over the border) the next day at no extra charge?