What I am disappointed is that by end game Igni does become the I-WIN button again. With 8 points of vigor, extremely fast vigor regeneration, and gear centered around improving sign damage Geralt became a walking fireball Gatling gun - sort of made other signs (with the exception of Quen) rather pointless.
I thought that might be the case, so have intentionally avoided putting points in igni at the moment, as I really don't want to make it to easy
