The only non-standard part other than the springs is the trigger bar, and unless you're getting the newest and greatest trigger bar from LTT, it is a Wilson trigger bar. LTT polishes up the contact points for the sear, hammer, trigger, trigger bar hammer strut and hammer/main spring. The trigger is SS matte finish. The hammer is a Beretta Elite. The trigger spring, sear spring and hammer spring are replacements and you can specify what spring weight you want on the hammer/main spring.
Wilson's action tune is likely polishing up the same parts that LTT does. I haven't felt a tuned Vertec, but I have handled a Centurion with the Wilson action job, and it was sweet. It was what convinced me something could be done to the Beretta to make it much nicer in the gun. Then I started my research. Keep something in mind. Ernest Langdon worked with/at Wilson at one time and basically taught them how to improve the 92. They are in competition, but I believe it is a friendly and respectful competition. I don't think you'll go wrong with either one. The differences between Wilson and LTT are mainly cosmetic. LTT starts with an M9A1 frame and Beretta dehorns the trigger guard and mag release areas to LTT specs so you don't get the knuckle callous. They add the extended Wilson mag release (same as Wilson) and a D hammer/main spring (same as Wilson). LTT and Wilson have steel triggers and guide rods. I think Wilson uses their spiral fluted recoil spring guide rod, but I'm not sure. Wilson rounds the trigger guard and cuts another cross slot on the light rail that makes it more 92A1 looking. I believe that is done by Beretta for Wilson. Both have the Elite hammer. Both have "G" conversions. LTT uses the Beretta Factory conversion, Wilson uses their own. LTT distinguishes their guns with the color accents, i.e. SS trigger, guide rod and barrel. Wilson's are black. Both have slim grips with slightly different checkering patterns made for them by VZ Grips. Wilson's have a logo medallion in the grips, LTT has their logo engraved in the grip. Wilson's standard are green for the 92 series, brown for the Vertec, LTT standard is black.
The 92x appears to use the M9A3 frame with a rounded trigger guard, but I can't verify that. One of the differences between the M9A3 frame and the old Vertec is the spacing of the grip screws. They aren't the same. I don't know what frame Wilson uses for their Vertec, whether it is the old, true Vertec frame, or the M9A3.
Both Wilson and LTT offer their trigger jobs. Wilson has parts, but they don't offer the TJIB option that LTT does. You won't go wrong with either one, it's more the subtle differences. But if you want a Vertec style frame, LTT doesn't offer one.