We went on the tour and Auschwitz I is very moving and I could not go in all the rooms, as I felt that the crowds and photo taking was a little disrespectful. We went out of season and it was really busy, tours like conveyer belts of people. We arrived early, thankfully because as we left for Auschwitz II the queue was horrendous.
It is moving, and we should remember the people behind the pictures and objects. Auschwitz II is Birkenau and not much to see there but the enormity of industrialised murder!
Be prepared for lots of walking, the tour lasts all day and you are on your feet all the time.More