Armed Citizens Defense Network put out a really good article on this topic with a heavy focus on reduced trigger weights. They are obviously going to take a very conservative stance here but it's well reasoned and they included a fair amount of input from industry experts. It's worth a read IMO...and I carry a modified gun (usually a M&P CORE with a Trijicon RMR and an Apex trigger).
by Marty Hayes, J.D.
Gun enthusiasts often challenge authoritative advice to avoid radically modifying their self-defense gun, reducing trigger pull weight or carrying it with hand-loaded ammunition for self defense. As gun lovers, as well as self-defense practitioners, many who argue these points find it difficult to separate the features of a gun that is fun to shoot from one that is difficult if not impossible to defend in court.