Hey TikkaMike, I used to shoot Action Pistol competition in N. Texas/S. Oklahoma in the early 90's and I totally agree with you - tons of fun! The people were awesome and I learned so much. Funny you are using a Glock 21 as that's what I started with, too. But I switched to a Glock 17 after a year because my wife was regularly beating me with her Glock 19, ha! She was a good shot. Very focused. At a match, I'd start off well, but as the round count went up, I'd start throwing shots away. Just a tad too much recoil for me out of that .45 ACP. But that was before the SF frames came along. I think that would have helped some.
Things I learned - your gun isn't truly squared away until you can shoot two matches with it and nothing goes wrong. I saw mags falling out of guns, front sights taking flight, and jam-a-matics galore. It was an eye opener. But...FUN! I hope you keep with it and have a great time for years to come.