I did it. Beat the final battle in ToB, and finished the whole BG series. Took me about 2 RL months to do. Whew. But well worth it, I really enjoyed the characters and dialogue, plus the lore and background. I don't think I've played such an engaging RPG in a long while.
The final battle was both hard and silly easy. The hard part was dealing with the Big Bad and her summoned minions swarming my party. Then I realized I could plop Spike Traps on her spawn point. Boom, final "final" battle done instantly after her speech. Don't think I remember any Final Boss / Big Bad being defeated instantly or no effort like that. Closest would be Cloud instant-Omnislash on Sephiroth in the ending battle in Final Fantasy 7, or Yu Yevon in Final Fantasy 10, or Luther (final boss) and the bonus bosses in Star Ocean 3 if geared properly, they'd do 0 damage to you with all forms of attack.
It even makes RP sense to pull the Spike Traps on the Big Bad. She spawns in the exact same spot 4 times. A thief would go "Hmm, she pops there again after the 2nd or 3rd time. Lets plop traps right there, just in case!"
I'd have liked a bit more closure to ToB though. Perhaps a short epilogue chapter where you meet and chat up with people in the Mortal-ending, or see your new Godly home in the God-ending.
A couple plot holes, though. Seems like the Big Bad and the Solar forgot that there's still other Bhaalspawn out there. Imoen and that "scared then explode-teleport away" one. And I'm not sure about Bhaal himself. Does one Bhaalspawn have to live with all others dead for Bhaal to resurrect, or do all the Bhaalspawn have to die for Bhaal to resurrect?
And what if cast Imprison on a Bhaalspawn with no other witnesses? Then that Bhaalspawn would be hidden away forever, Meaning Bhaal wouldn't be resurrected either way?
Will share more thoughts later.