I really enjoyed the holiday.
It is very easy riding - by any standards - a gravel surface, and the gradient limited by what trains could handle. Lots of people do it who haven't been on a bike for decades. Its 150 km and we took 3 days in one direction and 4 days coming back so only about 30 - 55 km a day. But the scenery and the history are really great.
Having trouble with getting some photos up - I'll try a few more things