I can't see how an inch difference at 25yds could give an advantage in an IDPA style match. I would think the increased sight radius of the 20 would more than make up for that in a "run and gun" type competition. GSSF is like IDPA, right?
The combustion of fuel being necessary for heating and cooking in the home, the right of the people to keep fire extinguishers shall not be infringed. - Alternate structural interpretation of the 2A (to protect the people from the state militia).