It all depends on how you ride.
If you are going over 40 on a suzuki samurai and do a J turn it will flip over...with a sway bar.
My buddy just got a new 16 RZR 1k... had it an hour and called us to come flip him back over because he stopped mid doughnut and flipped it over. With a sway bar.
It's not the sway bars fault. If you are going fast on a p5 and try to turn, you will have a bad day regardless.
It depends on how you use the p5, if it spends its days on gravel roads or pulling a parade float then it's a bonus.
But, if you are a rock crawler that moves through the mud and the woods at low speeds the sway bar is a negative and can cause a tire to lift off the ground, that is bad because you have no locker up front and it can also cause you to fall over. It stops articulation of the suspension... we don't have much suspension from the get go, so I need all I can get.
The aftermarket makes RZR air disconnects for the sway bars for the slow guys, because you need them in the dunes or on the track going fast and hardcore jeep guys also have these so once they get to the trail they can unhook..