Production vs. Limited in USPSA
There is no "advantage" per se because the competition is within divisions. For equally skilled competitors those in limited division will tend to have better overall scores than production due to not having to reload as often and more favorable scoring calculations.
Production is a class close-ish to IDPA's Stock Service Pistol division where loaded division magazine capacity is limited to 10+1 and the mods that are permissible to the gun are somewhat limited as will (trigger jobs, reliability work, different sights). All competitors in this division are scored minor so 9mm guns are the most common in this division. I think minimum minor power factor is somewhere around 125.
The Limited division allows loading as many rounds as your mag can hold and there are more permissible mods allowed (than Production). 40 S&W is the caliber of choice and you see a lot of STI and Glock guns in this division. Almost everyone in this division will shoot a load that meets the minimum power factor to be scored major (you get more points for marginal hits than minor power factor competitors). I think minumum power factor for major is around 165.
Many people like to shoot the Production division because it tends to be a bit less expensive of a game and many shooters also shoot IDPA and they can shoot the same gear in both games.