Yes, Lae'zel is a great character with a well-executed journey. I romanced her and there were some very sweet moments, such as when you duel her and, if you lose, Lae'zel
tears up and says she doesn't want to hurt the player, but to protect them, and be protected by them.
And, in general, when after/during the creche:
"I did not sin against Vlaakith, Vlaakith sinned against me!"
Like you say, she manages to keep her core identity while undergoing some big development. Of all the characters, Lae'zel is perhaps the one where Tav knows exactly where they stand and while she might just kill you, it'll only be when the present situation is resolved. Comparing her to everyone else (except Wyll who is terminally bland) demonstrates how honest and forthright she is -- she's just not a very nice person. But she's also young and naive in her own way, conducting herself like the perfect little Gith warrior with a status in their society she doesn't actually possess, and of all the characters you can travel with, I'd say she's one of the least morally objectionable.
Unfortunately, there are things that bother me. The first is the conflict between Shadowheart and Lae'zel which can culminate with Shadowheart pulling a knife on her and threatening to kill her and cover it up. There are no options to take Lae'zel's side beyond immediately killing Shadowheart. Which is a shame because Lae'zel is correct that Shadowheart is carrying a gith relic. I think this fight is supposed to fire off in one of your first long rests, when you don't know what the artifact is or does, but for me it happened well toward the end of the goblin camp and so it was just really weird. It's one of the few times where I thought BG3's reactivity was sorely lacking.
