If you plan to travel intensively in Germany, get ready with a generous budget. The country is huge and especially due to the Cold War limitations as well as to the geographical structure of the country as such, the railway network is complicated and a long trip by train involves a lot of stops. In addition, unless you plan your trip at least two weeks in advance, the costs of a spontaneous train adventures can be quite high. There are buses too, but get ready to spend a lot of time in your comfy chairs and especially if you are out of time, there may be not a convenient choice, despite the attractive prices.
In parallel with the official Deutsche Bahn network, regional trains, some of them operated by private companies, were created locally, with better prices and less delays. One of them, HEX, I used intensively during my latest trips to Harz mountains and I promise to use it again as often as possible.
The tickets can be bought in train, from the machines or directly from the personnel. Some combinations with Deutsche Bahn tickets can be possible - this is how I discovered them, after all, searching for a connection from Berlin to Quedlinburg, but only from Magdeburg on. The prices are very convenient especially the week-end offers that can go to 25 Euro pro person, two ways to any destination in Harz. Discounts are offered for the big groups of passengers and for children.
This region is lovely both in summer, autumn and winter - there is already snow there - so this train can be helpful for a variety of tourists and interests.
The train has only a couple of wagons that are going to different directions from certain points on. Everything - including the toilets - is clean and well kept, with smiling personnel that might offer you a piece of chocolate too, especially if a chocolate festival is organized in one of the cities part of the route. As the place is relatively small, there is not too much left for bikes, especially if you plan to go in a big group. Another inconvenient could be the lack of big tables for family meals in some trains. However, there may be free newspapers available that can help you survive an otherwise pleasant trip.
I've been with them already twice and planning to go soon in two more destinations.