At the ATO, you'll do work you can't do anywhere else. Work that is meaningful, diverse, and challenging.
Within the grad program, grads themselves have cliques. It can be quite hard to talk other grads as there is this sense of competition. Therefore, it makes it hard to ask for help in relation to work or something else. Personally, talking to people in organisation is a little hard. Also, in both of my 2 rotations it was not that common to talk your higher ups especially is they are SES and above.