There is nothing more exciting than travelling with train. Too heavy backpack on your shoulders, which is troubling you when putting it on too high clipboard for luggage in compartment of train. With Interrail ticket in your pocket. Randomly choosing train that you will take next. Gives you more flexibility of your travel , so you dont need to take exact same train that you have planned ,or that one which is written on your ticket. It is cheapest way to travel around europe , i think biggest advantages of train, when they are compared with planes, is that train stations are located in cities, lots of them are located close to the center of cities.
I have been using interrail one country pass for Germany 3 day ticket , paying 134€ , so and i travel with it from Munich to Flensburg almost 1000km distance. Taking usual ticket for ICE , from Munich to Hamburg would cost for 2nd class trip 129€ and then double that for going back , so Interail is good thing for such a low budget trips and saving loots on train cost, so more money for other things (museums, souvenir,...)
If you have a chance to travel with train take it. ;-)