Why not use exceptions as regular flow of control?

Question

To avoid all standard-answers I could have Googled on, I will provide an example you all can attack at will.

C# and Java (and too many others) have with plenty of ty

Answer 1

How about performance? While load testing a .NET web app we topped out at 100 simulated users per web server until we fixed a commonly-occuring exception and that number increased to 500 users.