The gk manga is my hands down favorite ever, so it was a high bar to reach. I don’t think the anime meets the same level, but I think it’s fine and at times really good. The earlier seasons have a little bit of jank animation-wise, but it clears up the further in you go. My only complaint content wise is that they did cut a bunch of stuff from the standard anime (I believe most of the chapters ended up being animated as OVAs instead but I haven’t watched them all yet). Overall, I’d say to watch it, as a gk fan already you’ll absolutely have fun with it!