Hi, Nekryu,
I've been playing this game on an M1 MacBook Pro and have reached Ch 4 with (so far) no performance issues. I'm using the "High" graphics settings but haven't bothered checking out "Ultra" since everything looks good and runs fine on default settings.
I'd recommend you buy this game if this summary appeals to you: It successfully (in my view) recaptures the look and feel of Baldur's Gate, Iceland Dale and related Infinity Engine games, without being a carbon copy or being tied to D&D mechanics. On reflection, I think Ive been disappointed in Pathfinder, POE and Baldur's Gate 3 not so much in their mechanics or character class/race options or fidelity to D&D, but that they weren't all that fun to actually play. This game has far fewer options (currently) compared to its better-funded competition, but I'm having a LOT of flashback fun encountering quests and characters that wouldn't have at all been out of place in the original Baldur's Gate. The differences in combat, spell casting, leveling, etc doesn't get in the way of the nostalgic fun, and I appreciate that a LOT! If the nostalgia factor isn't relevant for you, this game will probably still be worth checking out, but you will have more smiles along the way if you loved the game(s) that inspired this one.
Hope this helps!
Dan