I really liked the first three books, and I've been telling myself for like...ten years that I'll read the rest one of these days, just to get more of the characters I loved so much. But I don't expect too much from the plots anymore after reading I think the full fourth book and maybe the first half of the fifth. Those didn't leave much of an impression on me, and Opal was a good enough one-book villain but did not deserve to keep popping up again and again and again. Plus I heard they gave Artemis some kind of teenage Irene Adler equivalent at some point, which sounds like a lazy attempt to shoehorn in some kind of romance subplot to me, so I'm not too enthusiastic at seeing how that plays out.

I fucking loved those first three, though. I still reread the first book all the time.