I think CA touched slightly on the most important sense for noticing experience: feel.
I may not be able to always see the nuances that make my sensei a 4th dan and a fellow aikidoka not quite shodan during technique demonstrations, but I can certainly feel the difference when it is my turn to become uke and I receive the techniques. Whether one is wearing a hakama or not, the evidence of experience is most clearly conveyed through technique.
Even if you blindfolded me, I think I'd be able to distinguish the sparse, precise movements of my sensei from anyone else in the dojo.
2 cent refund in NY only.