My impression so far after reading more than a few comments is that not everyone necessarily means the same thing when they use the term "turn based." From a lot of experience playing a lot of tactical war games and strategic war games I have learned "turn based" can mean a variety of things. The possibilities include:
* IGoUGo without reaction - I go, you go, I go, you go, etc. etc. Neither side gets to react to what the other side does until the next turn. No changes to any orders except at the start of each player's turn.
* IGoUGo with reaction - I go & you get to react; you go & I get to react; I go & you get to react; you go and I get to react; etc. etc. No changes to any orders except at the start of each player's turn. Reactions are typically firing and returning fire, maybe stopping movement for the side that is on its turn.
* IGoUGo in phases with reaction - I go in phases (typically a function of unit speed and/or firing rate) & you get to react with firing to each of my actions; you go in phases & I get to react to each of your actions. Typically the player on turn gets to move, fire, stop movement at any phase, and return fire. Reactions for the other side are firing and returning fire. No other changes to orders except at the start of each player's turn. For D&D purposes phases are the 10 initiative segments during a turn. But then is the current rule set 10 minute turns with 1 minute segments broken down into 6 second initiative segments? Or are is it now 1 minute turns with 10 6 second segments? I've lost track.
* WEGO without reaction - I go and you go (aka wego) at the same time after we both issue all of our orders. No reaction to what the other side does.
* WEGO with reaction - I go and you go at the same time after we both issue all of our orders. We both get to react, typically by firing and returning fire, to what the other side does, and maybe have the option to stop movement.
* WEGO in phases with reaction. We both issue orders at the same, we both go/execute our orders at the same time once the turn beings, and at each phase of the turn we can both react by stopping movement, firing, and/or returning fire.

Consequently, when people here refer to "Turn Based," I'm not 100% sure what they mean. If "turn based" for BGIII means IGoUGo then I would hate that. IGoUGo turn based playing is fine for chess or checkers or cards, but a terrible idea in an RPG that is trying to simulate what we might be able to do in a real world. If I were really fighting someone in a dungeon or field or street I wouldn't have to stand there helplessly and watch and wait while the other side does whatever the other side is going to do. I would be simultaneously doing my thing and reacting to what my opponent is doing. Therefore, in an RPG, I think the two best ways to simulate real activity is either by doing RTwP or by doing a turn based phased WEGO with reaction approach. Ideally, the best option would be to do or permit both. One of the wonderful things about the Icewind Dale series, BG, & BG II (just to name a few) was that they were RTwP plus the option to select a variety of auto pause triggers that include but are not limited to: End of each turn; spell is cast; any member of the party takes damage; any member of the party dies. We need to have the ability to react whenever necessary to what the other side does during the dynamic ebb and flow of a hectic battle. The thing is, they were also turn based. It's just that the turns happened transparently behind the scenes as the computer dealt with the mechanics and timing of each turn.

Now, I can see some kind of turn based RPG working if the only character I'm controlling is my own player character, plus maybe one henchman. But a full party of six, or what looks like will only be four for BGIII? No way. Too much happens when a party of six, or four, is fighting as many if not more opponents. If I start to do one thing, say move to the other side of a room to flank someone, I need the option to instead stop and fire an arrow when I see a Mage in the back starting to cast a spell because tactically stopping that spell caster suddenly became more important than moving to flank someone. Forcing me to helplessly continue moving just because that was the last order I gave instead of being able to react to dynamic changes in the flow of battle and changes to the other side's tactics would be terribly frustrating. I would hate it and I can't see me standing that for more than a few hours of play. Often in all of those old D&D games I mentioned my party of six was seriously outnumbered. Proper tactics, and the ability to pause and change orders in reaction to the dynamic changes of combat, was what made survival possible. Proper tactics and reactively changing tactics on the fly by using RTwP were the keys to success in those old full party D&D games. At least that was the case for anyone who wanted to micromanage the whole party instead of controlling only our player character.

So, for me, the bottom line is my overwhelming first choice is RTwP. IF we do get stuck with turn based game I pray that it will be a phased WEGO with reaction. That is the next best thing to RTwP when it comes to being able to react to the dynamic changes and ebb and flow of intense combat.