Just found this forum, very excited, wanted to jump into the first ragin' debate and give my 2 shekels..
From a very, very general perspective, and I mean after just watching a few second's worth of footage of the 2 systems... this should be fairly simple I'd think. This is Baldur's Gate... it's gotta be RTWP, doesn't it?
Baldurs Gate is just not a game in which once combat begins, your characters are standing still, doing.. 'animations'... while waiting for their turn. It's just not part of it's identity. It's not part of it's design.
I get that this is a fundamental characteristic of Turn Based combat and an identifying feature of what that style of combat is and what it looks like (and I fully get that building your game around that system is a legit and successful style of game design). But the pace of BG was never that segmented. It is intense and punishing because of how that Space Bar effects everything. It ushered PnP tabletop into the digital age where you no longer have to wait. It transformed the state of computer RPG's forever.
If Larian agreed to take the reigns of an epic franchise like this, and they are not planning on totally changing something that central to the franchise's identity, then I honestly can't imagine this is even a question for them.
Again, so excited to be here! Thanks Larian and Good Luck!!!