A professional is able to shoot with any cameras (but most of them will prefer using top of the range cameras for many reasons), and will not look down any other photographers with a more consumer level cameras. Cos we believe that in the end of the day, who can deliver results is the King.
and I notice some people are very upset to see a professional using a lower grade camera compare to what their are holding in their hands, so many issues arises.
Most of the pros are not really concern about this, to deliver results and get paid are far more important than boasting self ego.
Long long time ago, I was so cheesed with those "what camera you using today ah?" bystanders that I whipped out my back up PnS (Yashica T*4) and started snapping... you should see that bugger's face!