Guess I can confess now that I exited USPSA competition about 20 years ago. I built up a 1911 purely for competition. Having shot my first classification courses and immediately classed myself into the middle of the C-class pack, I felt I needed every little bit of advantage I could get. Got myself a nice Ernie Hill belt system, holster and mag carriers, had a BoMar rear sight installed, chamber reamed a Bar-Sto barrel for better feeding, and practiced a lot. Also played with spring rates and bullet weights, trying to get the muzzle back on target as fast as possible because I wanted to win and move up.
One of my last efforts was to mess with the recoil spring guide. I had a Wilson Group Gripper, full length rod with the back hollowed out and a cross pin that held a leaf spring. Interesting contraption. I removed the spring, melted some lead, and filled the rod with lead, the cross spring did a great job of retaining the lead. It added a little more weight ahead of the trigger area and no one bothered to weigh my customized 1911. In addition to becoming an IPSC/USPSA certified range officer, I made B-class and was eyeing the relatively new (at the time) Para-Ordnance receivers and an A-class card when an injury ended my competition semi-career.
So there may be, or at least once upon a time there was, an advantage to the full length guide rod.