Hi....If you can only do one of them...I would recommend the chopper. It is an amazing experience. My trip to the heart of Australia would have not been the same without it. The walk is good and enjoyable. Try to take a net to save your face from the flies. Otherwise it is an easy walk. I wouldnt do the climbing of the rock, it would show a lack of respect for Aboriginal Culture and their sacred places. Combine the Olgas and Uluru to make the most of it! We did the sunset helicopter trip and even though it was a bit overcast ....was magnificent nontheless!