I ride a variety of trails including steep, rocky ones, as well as easier dirt, rooty ones. At first, my dualie seemed better because it absorbed bumps better. But as I ride more and improve, I find that, to my surprise, I now like my hardtail better. The hardtail is more nimble and climbs better. Hardtail absorbs shocks nearly as well as the dualie since I get off seat to absorb rough stuff on both.
Perhaps I'm not using the dualie properly, as standing when I could be sitting. I have used my hardtail and dualie the same amount of time.
Which -- a hardtail or a dualie -- do you prefer for a wide variety of cross country trail riding?