Well, he is correct. I have the P365 and the P365 XL along with the P320. I put the subcompact grip module on the 320 and tried it but did not like it. It just didn’t seem to give me enough purchase on the grip to control the weapon properly. I wound up putting the Wilson combat carry grip module on the pistol and could not be more pleased. One of our members characterized the Sig P320 grip as a “potato” and I think that’s pretty accurate. On the subcompact it’s a short potato.
As far as shootability, I would rate the P365 XL at the top. I would rate the P365 next and the P320 subcompact last. The grip on the 320 subcompact just didn’t work for me. For me, I found that the subcompact did not have as repeatable a grip. In other words, I felt as if I were milking the grip a little bit to get to my preferred hold after practicing from a draw. The XL and the P365 were both very consistent.
Now if you include the standard Carry P320, I think that pistol, particularly with the Wilson combat grip module rules them all. I believe all the models are plenty accurate for defensive purposes. I hope I answered your questions and if you would like any more information, please let me know.