This titanium striker has really been the best internal upgrade by far. The fact that the plastic housing is now eliminated and the spring is lighter along with all the machined aspects truely has transformed this pistol. The drag and grit is gone replaced by responsive feedback.
I used it on 124gr CCI Blazer fmj, Sig V-Crown 124gr, MagTech 115gr and Federal HST +P 124, all with no issues at all. My particular 365 has many aftermarket parts but the fire-control system is stock Sig save for MCarbo's sprink kit. Now it sports under 4.4 pounds total pull with the included 3 pound main spring yet it feels so much lighter while still being safe. Note that the trigger spring kit has a 4lbs spring for the striker, which yeilded 5.5lbs trigger pull at peak, barely more if any want nearly the same feel. Very very pleased with this striker. No light hits at all, just seemless, fast and clean. Feels like a $1,000 pistol.