The "round-based RTwP" implementation of AD&D in the Infinity Engine games is great IMO because it's a very controlled form of RTwP. Understanding how often units can act is very simple and it's also very easy to 'read' on the screen without the need for on-screen UI elements to explain it. I think it was a mistake on Obsidian's part to dis it because it demonstrates their lack of understanding one of the key things that made the IE combat feel good. The only thing I think was a bit lacking was in-game explanation of how it worked (which Pillars also suffers from, possibly even moreso).
It's not controlled at all, in fact I'd say its only strength is the fact that it's wild and unbalanced in an entertaining way. I think you feel that way because it's very limited and incredibly one-dimensional. The lack of information required for me isn't a bonus, it's a preference, I don't mind having to learn about the game before being able to properly read what's going on or just having to guess what happened every now and then. IE's design is lifted straight from P&P rules, which of course makes it very easy to read, because it's made to be easy so a person with a pen can quickly formulate it with extremely abstract variants, which there are as little as possible to not create convoluted algebra equations. Besides, for me IE combat didn't feel good at all, it felt extremely anti-climactic, floaty and not rewarding at all, it's like a RTS combat with even less complexity but without the rest of the game's systems to back it up.
The ruleset for attack speed was a lot better as well - character start with a base of 1 that is increased at certain levels, with certain proficiency points and through item or spell use. The value of an increase or decrease in attacks per round is very easy to comprehend mentally and visually in combat. The system in Pillars is bloated and confusing by comparison and I think we'll see a definite change to the formula in the sequel (although not necessarily a stylistic change).
Pillars' is a much more complex system, so if your preference is for more clarity, I can understand why you might not like it, that's completely okay for me but then again it's preference. However I will disagree with base attack per round being "a lot" better, I'd say it was a lot more streamlined, which makes combat feel like it is supposed to be turn-based but is in a real-time realm for what-ever-reason. Especially since everything felt so out of place in combat, the void attack animations and ability to move after using your attack limit that round. I don't understand why someone would just not make the game turn-based if they go as far to make it play like one.
I don't think the AD&D implementation in the IE games was perfect but I do enjoy the gameplay that comes from it more than the gameplay that came from implementations of the later editions. Black Isle's 3E Infinity Engine version was inferior from a gameplay perspective IMO. I think it added more choice to the character creation and advancement, but I don't think it contributed to better gameplay.
Choice in character creation and advancement IS gameplay. They are not separate realms that are disconnected from each other, split-second tactical decisions aren't all there is to gameplay, in fact those for me feel more like a chore rather than gameplay.
All in all it's a preference for an old but known system, I am glad RPG designers moved away from an era of lost game developers that didn't know whether to recreate a visual representation of a tabletop session or a game on its ownright. In fact, BG feels a lot like it is a tabletop session rather than a separate medium, not only in its appropriated combat systems but also in its overall writing and narrative style. Which to me is an extremely niche acquired-taste from people who got into video games with that system in particular.
It's a chapter of video game design that I am glad existed as a stepping stone. The missing link required for transitioning p&p rules into something more complex and with less abstractions because computers can make the calculations. Turn-based are better if you want a streamlined round-based system with maximum clarity anyhow. Hell, I can't see why you would want "real-time" instead of turn-based if you have rounds in a game other than a desire to micro-manage character movements on an 2D plane.