Are there any consequences for letting the succubi in the game live? I have not found any. Also, do you spare or kill them? I let the first one go, and killed the second one that was in the alchemy quest.

I let them both go and never saw anything else about it.

It's to bad, the Geralt of Old would have at least been given the oppertunity to bed down the succubous as we saw in TW2. If you kill them you get the mutagen for the decotion. I have only thus far come across 1, she wasn't really a looker or anything but it would be nice if the option were there. I mean this is a creature whom seduces men, I'm at a loss as to why we didn't see that option.

So I spared her life, unfortunatly that meant running her out of town, when I'd have rather left her there killing off those corrupted guards/witch hunters.

No consequences as far as I can see. I let them live.

Maybe in one of the extensions we'll meet one of them again.