The Githyanki encounter is challenging, but not like Drizzt in BG1 was.
Well, Drizzt in BG1 (and 2) wasn't even supposed to be "an encounter", strictly speaking.
It was a easter egg/cameo from a "D&D celebriity" that the Murderhobo player had to go out of his way to turn into an actual fight.
Like when you met Elminster during Throne of Bhaal (except in that case I don't think you could actually fight him no matter what you did? It's been a while).