I'll post my thoughts on this matter from my thread here as well:
The turn based combat & team initiative is honestly a much better combat mode for the game than RT+pause. I still play the original games this day, but I use a mod called Sword Coast Stratagems that makes the game a lot more challenging, partly by giving enemy spellcasters the same advantages you have (pre-cast buffs & protection spells etc.). There's a reason they were nerfed in the original game: RT+pause is just not a very good system for tactical combat. You have to set the autopause settings very tight if you want full control over your characters, which makes the game super slow. Also the characters aren't super responsive, meaning that sometimes they don't act on their turn but on the next turn, which might mean they're dead. So, the IE games are great but the combat was somewhat chaotic, I always felt I lacked control over my characters.
I don't know if anyone remembers games like Jagged Allience 2 (the greatest turn based RPG ever made) or Temple Of Elemental Evil (great combat, flawed game otherwise) but both actually had better combat than the IE games due to being turn based. Now a game doesn't have to have tactical combat to be good, but I think that D&D with all the different abilities and characters works best when you have to most control in battle, which basically means turn based.