I think in a lot of cases, knowledge turned out to be too much power. Encounters could go from impossible to trivial with the right spells (the Demi Lich, for example). So tactics mostly amounted to figuring out how to shut down the enemy mages and letting your fighters beat the crap out of everything. A lot of the rest was about exploiting AI weaknesses. For example, efficiently combating Timestop was a matter of summoning a level 1 monster to be the closest ally to the enemy caster at the start of battle.
I jumped into PoE directly from a playthrough of BG2:EE (I'm 3/4 of the way through the ToB expansion), and so far I really like the direction Obsidian has taken this game. Combat tactics are more dynamic, and I feel like I have more options in terms of what constitutes a winning strategy. The game may not be as hard overall on Normal difficulty, but I also don't feel like there's such a sharp swing between a winning strategy and everything else.
Also, I absolutely love than experience is quest-oriented rather than combat-oriented, because it makes me feel more inclined to find ways around encounters rather than razing a dungeon for the XP. From a tactics perspective, that provides even more options that I wouldn't have considered before. For example, in the beginning of PoE there's a cave with a bear and a corpse. I walked in, solo, and cast a confusion spell on the bear, which gave me enough time to investigate the corpse and escape. Never would have done that in a BG game.