The big difference for me is the characters. I genuinely cared about Minsc (and Boo), I kept Jaheira with me as Gorion would have wanted it. I loved Edwin's arrogance and I had a crush on Viconia (I was 14). At the moment I like Gale as a character, I find Astarion intriguing but I can't work out if he wants to escape his evil ways or not. Wyll is OK but no big impressions. Shadowheart and Lae'zel are just plain annoying. I have done several play throughs of the pre-release good and evil, and rather than relaxing and playing much like I did with BG1 and BG2 I find myself on edge playing this game. One misstep and you're dead, engage in melee and your dead. I have only played the NWN and BG series. Obviously graphics and stuff have come a long way, but decision trees in coding as well as building a good story are still the same. The characters and genuinely caring for them is where it is at. Zevlor is the only character I really seem to care about.
There is no equivalent of 'Magic is impressive, but now Misc leads swords for everyone!'.....well not yet anyway.
On a plus side I must say I am really pleased to have Larian do this. Everyone is talking about DOS and DOS2 but I have never heard of them or played them. Perhaps when i've finished BG3 I'll have a look.
The start is definitely different, in that you create your own background and are thrown into the action. In BG 1 you are given a background in a town , and a quest to meet Harper contacts...it felt like a D&D story.
The characters in this story feel too much like modern day, Covid-19 era, rude and crude earthlings. Being thrown into the action is a great idea...however the developers did nothing to make us feel like we were in Faerun. I want to escape the stress of a society which is in an identity crisis.
The Adventurer's Club, in the old Disney Pleasure Island was immersive because there would be thespians wandering around that would convincingly act out their memes.
So far this doesn't feel like Faerun, nor does it feel like a D&D rule set like BG1-2 did (more like DOS). It feels like its having an identity crisis.
This is BETA, where comments like this are meant to matter...so lets not take offense please.