@Xzarloxara
I actually prefer to play without SCS. Call me a filthy casual but the game is hard enough by itself lol. I do have the AI Improvements from the Quest Pack and the improved Final Battle but none of the other improved battles from Ascension. I don't think I'm ready for those.
I used to think so too that the game is hard enough and SCS looked intimidating, but I didn't find that to be the case, at least not in BG:EE. I haven't reached BG2 with it yet, some of the spell nerfs if you do a full install might have a nasty impact, I don't know.
But except for the fact that it was like playing a new game, without knowing what to expect from which enemy, I can't say I found BG:EE with SCS harder than without, even using it for the first time and on the highest difficulty (with the damage increase of the vanilla game difficulty setting disabled though. I wanted them to be smart, not an earthquake). The statement that "SCS plays fair" is not just advertisement. If someone is used to the biggest cheese, it might be harder, but actually most changes just make the enemy smarter, more like another player, and the fairness goes both ways. You pre-buff, they pre-buff. They don't cast the same spell repeatedly on someone who is obviously immune to it, but they also don't hack the incapacitated party member (or protagonist) to death when others are alive and threatening, as I found out the first time I ran into an ogre mage and failed to dodge the Sleep spell.
So if you're not ready for a change to the game you know so well, that's another matter, but I wouldn't fear the difficulty threshold, and besides it's highly customizable.