Each new Ultima game in the series pushed the envelope and that was always a trademark of the series. But Ultima 8 was a big divergence from the formula with you being on a different planet with a different magic system. I don't think Iolo, Shamino or the others were around either. Did the game allow parties? Was the world as large as Ultima 7? To be honest I never played Ultima 8 that much. The graphics looked good but the addition of jumping and jumping puzzles didn't go over with a lot of people. After the masterpiece that was Ultima 7, it stands to reason that many people expected the envelope to be pushed more but instead Richard Garriott wanted (or perhaps EA did) to broaden the market a bit by trying to appeal to a wider audience, at the expense of alienating some of the traditional audience. Was the environment still as interactive in Ultima 8 as in Ultima 7? I don't think it was. I certainly don't agree that graphics style is more important than gameplay. You can have both but if I had to choose I would choose gameplay. How many references to the previous games were in Ultima 8? It really seemed to me to be a very different game than the previous games in the series. An experiment perhaps but Garriott I think eventually indicated he would go back to roots more in Ultima 9 (and I am not sure that he did).
I never played Ultima 9. The biggest complaints I hear is that the graphics engine ran very slowly and the game was buggy. Not sure if it had a party either and they didn't go with the original ending as planned for the storyline either. The fact that the game's lead designer changed one or twice during development must not have helped it.