Honestly, I wished I hadn't played the early access build because that was the story I ended up wanting to see continued.
This resonates so much with me. Not only was it a mistake to change that character, I think it's probably the biggest drag on the game's story altogether.
Overall, the Guardian is just a thematically weak, bland mystery box full of lost potential. While there is some ambiguity to the character that never made me quite trust them, I think the old one was more compelling simply by virtue of actually
interacting with your character. All the Guardian does is assure you that you're doing the right thing because your interests are completely aligned while also telling you alien brainworms are safe for consumption according to the FDA. It never gets any deeper than that and the game doesn't really give you a choice in how you approach the character either.
The dream visitor from early access on the other hand felt like they actually
wanted something from us and was ready to promise us something in return. It also felt so much more personal and intimate like an actual, intelligent evil pulling all registers trying to seduce you with power while you're in a position of weakness. It worked because of the desperate state our player characters found themselves in and it felt like it was actually going somewhere, leading your character to a point where they would have to make an important choice. There was also the implication of a slumbering dark urge turning you against the dream visitor which we never got to see explored - just like we never see the consequences of using the parasite explored. All in all it was a much more interesting experience and if it had spared us of that horrible catfishing squid character (who is also somehow a very important lore figure) - all the better.