I'm going to regret this damning statement but, DQ8 is for casuals and DQ virgins. DQ8 was my first DQ, and I loved it. Then I went back - after playing the entire series. Its dungeons are terrible, it reuses entire storylines, alchemy pot sucks, battles are atrociously long in favor of classic DQ swiftness. DQ9 is objectively better than 8 in almost every single category, short of characters, and MAYBE story. And DQ has never been about characters, aside from VIII. DQ is about the world, the world and its vignettes are the characters these people crave.
If graphics and characters are your priority, sure, DQIX may be a step back!