The striker portion is a bit taller, thus less prone to underslip the firing pin upon hammer impact, especially if the trigger extension is perhaps a bit on the short side to hold the lifter portion well up in place.
The currently used T-bar assembly is, as I understand it, being used on all production models (the change point is not known) and, yes, it would be, IMHO, along with the trigger extention, well worth installing in any Handi which is problematic on FTF syndrome.