RTwP: you play a party, pause the game, execute orders and everyone, including the enemy, move simultaneously and you can react and adjust actions on the fly.
Simultaneous execution without a clusterfuck of brittle overwatch, interrupt, AoO, etc. rules and lack of reaction delay are without doubts advantages of RTwP (or any other RT) system.
But in practice they are eclipsed by the sheer awkwardness of it.
And, of course, it goes without saying that adapting TB to RTWP while still retaining inherent coarseness of underlying (TB) mechanics (like in IE games) is just fucking atrocity with no redeeming qualities whatsoever.
Good for simulating the chaos of a battle, but on the downside it can also lead to frustrating clusterfuck and it's easy to misclick and can be hard to keep track of things in large battles.
RT
without P is even better at simulating the chaos of battle. It also doesn't inherit the main drawback of RTwP which is mashing pause. It is lousy at allowing player execute complex tactics, though. Because it's so good at simulating chaos of battle.
RTwP mostly fails by trying to have it both ways. Both RT and TB/PB are just better for their respective niches.
What could be a genuinely good RTw* system, though, without it being a political marriage of incompatible traits working cross-purposes, would be a
real time with slo-mo.
Basically, you have RT system where, instead of (or besides) pause you have ability to quickly and fluently adjust game speed (panic mode and snap back to 1x included). That means you could adjust the pace to allow effectively the same flow of control as RTWP, but without having to pause and unpause the game several times a second (game time), it would just flow at the rate where player could stay responsive and in control, without artificiality and annoyance of pausing.