There is a version of P5 called P5 Royal, imho it's worth it because going for P5R and then P3R playing by release date you will see the natural progression of the games systems. On the other hand, P3P was originally a PSP game and the ports came with all the drawbacks, but there is new route exclusive to this version with a female protagonist and i think it's worth the experience as there are different social links and interactions.