Comparing it to Persona 4 and 5 (arguably perfect games) is a fool's errand, and even if it doesn't execute every idea as perfectly as its sequels, it's still one of the best JRPGs of all time.
The one thing I'll warn potential players about: Persona 3 takes a while to show its hand. If you're like me, you're probably going to get 1/3—1/2 through the game before the intrigue really sets in, which can make the opening hours feel a little odd. However, if you stick it out and allow yourself to get invested, you will be richly rewarded.
It's also worth noting that P3 Portable lacks an epilogue that is present in P3: FES, but after some research, I honestly think you'll be totally fine without it. I know I was.
The one thing I'll warn potential players about: Persona 3 takes a while to show its hand. If you're like me, you're probably going to get 1/3—1/2 through the game before the intrigue really sets in, which can make the opening hours feel a little odd. However, if you stick it out and allow yourself to get invested, you will be richly rewarded.
It's also worth noting that P3 Portable lacks an epilogue that is present in P3: FES, but after some research, I honestly think you'll be totally fine without it. I know I was.