I worked in a gun shop for many years. I've never been a fan of the convertible handgun. People buy the gun but rarely buy the conversion kits. It's a gun designed around an armorer configuring a handgun to the job but I'm not convinced it is practical. It looks like they sold the concept to some DPs and military based on the concept of repairing guns with universal interchangeable parts. Isn't part of the fun of gun ownership to buy more than one gun? A 1911, small carry pistol, revolver, competition guns, all types of rifles, shotguns of all sizes, metal guns, plastic guns and different calibers....
BTW - a 6.5 pound trigger isn't really that light. However, the real thing that makes a trigger good is a consistent, crisp break with little to no over-travel and a quick reset.
Sorry, but I always saw the convertible gun as a solution trying to find a problem that most civilian gun owners don't have. Sorry, Sig. I like your metal guns (especially the single action X-5s) but there are better plastic ones out there today.