I think the combat is absolutely fantastic, and the fact you positioned yourself without thinking what might happen, will probably teach you a lesson for the future

You think the combat takes too long? Have you ever sat at a D&D table and fought a large battle - you'd probably be there 3 weekends running, LOL. Obviously there will be tweaking, but the basic premise of the game is awesome. Great job, Larian!
I had one large battle that took about 4 sessions. I don't think it turned out that great though, and I was the one DMing!
It's something that I think I'd like to avoid in future, or come up with more creative solutions for. It's hard because our group has so many responsibilities (kids, partners, jobs) that when we get time to play together, it can feel really trying when all you've accomplished is a few more turns of the same combat. It's the same with a video game.
I'm down with the game's premise, but this is the place for feedback