A couple of Videos about the Meprolight FT Bullseye Sight:
https://www.youtube.com/watch?v=T9mCK3hV1gE
I think that he gives a good explanation Pros and Cons and what to expect from a Meprolight FT Bullseye sight:
https://www.youtube.com/watch?v=-S7J3o54HsY
I will say this..
If you are removing traditional Iron Sights Front / Rear from a slide in favor of this sight..in the end you can go back to traditional Iron sights should you want to.
With the P365SAS you do not easily have that option..
There is no front dovetail for a front sight and to add a rear iron sight you would need a rear plate to go into the slide.
It is a commitment to the Meprolight FT Bullseye Sighting System.