I once believed as many do - they perform in Saddleseat and Fine Harness, and that's it.... after meeting and owning my first I learned better. It may be what they are currently best known for, but, originally they WERE the "everything horse"!
I now own mainly Saddlebreds, and have never looked back. The intelligence, athletism, willingness to TRY are unmatched by any other breed (on the whole) that I have ever worked with!
Here is a picture of my saddlebred, this is very long ago. She has passed away in '04. I havent owned a Saddlebred since, but they will always be my favorite breed. We always won the showmanship classes.