Just out of curiosity, what is the preference here among professional pilots for flight cases - wheels or no wheels?

We are talking about the standard 19" x 14" x 9" case. I know there are other considerations for the type of aircraft you are flying and whether or not it will fit if a case with wheels is that much bigger. The other side is you can always hang it on your rolling luggage. I am just asking, all things being equal would you prefer wheels or no wheels?

Depends on whether I have to check my luggage or not, like the EU guys do.