I think you need to define the purpose of competition in your... I guess... "shooting life."
Examples:
1: Some folks don't live near a range where they can actually draw from a holster and shoot a drill because of range rules. A match can provide an exception to this rule for them, and after extensive dry fire practice they can validate with live fire at a match. This guy should probably shoot his carry rig. (It is easy to forget that a good chunk of the gun owning public is in this situation. Especially if you can drive 15 minutes to a private range and do whatever the hell you want.)
2: If you live somewhere with easy access to a range where you can keep up your holster skills with whatever you carry, and are proficient with your carry rig... changing out to a competition oriented gun can yield improved results in matches.
Also... if your goal in competition is to flat out win matches and not to get some practice with carry gear... there is a reason that top notch winning shooters use Glock 34's and not 19's or Tangfoglio Stock II's and not CZ P01's or Rami's.