I printed my own trigger to increase the overall reach for my large hands. I designed a small nub at the bottom to help locate the finger. Otherwise I like the flat profile. I also wanted the trigger face to be vertical at rest (not angled forward or backward). I think that helps provide a consistent reach and presentation on the clock in USPSA.

When I designed the trigger above I went through a number of iterations that also included just a flat profile. Ultimately I chose to include a slight recession to help locate the finger and provide a constant finger placement. The TSO (and other SAO CZ's) have a very short, light trigger pull so it isn't as important to have consistent finger location. With enough dryfire, it becomes unconscious. I also printed a DA/SA trigger for my Accushadow 2, and it has a curve to it. With the long DA first shot pull, it helps to have your finger properly located. Plus due to the long pull, the trigger has to fit in the trigger guard throughout the stroke.
Cheers,
Toby