Alex, the most successful elements of dreaming presented by the film are those that resonate with our actual experience of dreaming. Thus, time dilation is brilliant. Most of us experience that in dreams, so it was a fun element to have it quantified and further expounded such that the dilation became greater the deeper the levels you experience.
On that note, another resonant concept - in fact, the underpinning of the entire move - is that there are dreams within dreams. I daresay most of us have experienced that. I know I have.
The audience doesn't need to be convinced of these concepts. They have experienced them. But, yeah, totems are bullsh!t.
