The 5.7 is not a typical pistol cartridge. It’s closer to a 223 than a 45, especially with armor piercing ammo.
Hey, I’m not responding to start a caliber war, I’m just saying that the 5.7 round was developed as a replacement for the 9 mm. It was not intended to replace the 5.56 and as designed it fulfills a certain roll well. It is just not something that I’m interested in. If you like it and it fills the roll you want it for, more power to you. A person is better with a .22 LR that they can shoot quarters with at a 100 yds than a 50 BMG they can’t hit the side of a barn with.
If you want to use the suppressor as a flash hider and to suppress muzzle blast only then that’s your choice, nothing wrong with it. I definitely wouldn’t feel unarmed with that setup.
You might want to check on availability of AP rounds for the 5.7, they were restricted to LE and MIL unlike the .223 penetrators.