I think some of the best voices they have are characters like Twilight, she shows a ton of promise. But as it stands right now, I would still at least hesitate to use Twilight's voice in a project unless I didn't have other options. Chrysalis's voice is good, but again, is an exaggerated cartoon character with a large amount of inflection. I would not use her voice in her current state without a lot of post-processing. Someone like the Spy I would consider to be unusable, it sounds to me like the character needs to clear their throat or something, it's got a lot of strange artifacts. I definitely would consider the 10th Doctor unusable, even for just a hobby project or a voice assistant.

But... I don't know, maybe this is subjective. I can't just tell you that what you're hearing is wrong, if you like the results then you like the results :)

And again, I don't want to detract from how impressive they are. They are incredibly impressive, particularly because of how characters like Chrysalis emote. Extremely promising. But I still think there's a difference between 'impressive' and 'believable deepfake'.