Keep in mind the PS90 is a Personal Defense Weapon not an Assault Rifle. It is meant for armor crew members, pilots or anyone needing a small portable weapon that is better than a pistol for its primary intended use.
Google 5.7x28 terminal ballistics
SS197 40 gr V-Max (2100 ft/s out of PS90) 5.7x28: approx 267 lbf-ft at 100 yd
SS195 28 gr JHP (2480 ft/s out of PS90) 5.7x28: approx 266 lbf-ft @ 100 yd
SS196 40 gr V-max (1900 ft/s out of PS90) 5.7x28: approx 218 lbf-ft @ 100 yd
At 200 yards with a 40gr bullet the energy is around 150 lbf-ft
Basically, it's a tad stronger than .22LR out of the muzzle...lol
200 yards is about the outside edge of the weapons effective range. The P90, at close range with a happy switch and a 50 rd mag is going to ruin your day. At 200 yards I would rather have something else.
If you plan to engage at average distances of 200 yards you really should get a 223 or 308, there are far better weapons and far better rounds, especially for self-defense.