Here's a good article on it.
https://canikfanatik.com/2018/12/30/difference-between-all-canik-striker-models-tp9-v2-sa-sf-elites-da-sfx-sft-elite-combat/

John, the TP9-SA Mod 2 now has a flat top like many other Canik models including the Elite, SF, DA, SFL etc. They also removed the ambi decocker and made it right hand only, just like the very popular TP9DA. The Mod 2's decocking lever is considerably stiffer than the original to ease the mostly unwarranted concerns of accidentally disabling the gun.