Side by side, I much preferred the 805. There IS a SMALL bit more bass with the 804, but the drivers seem much more integrated with the 805 vs the 804, because of the smaller distance between the drivers (2 on the 805 vs 3 on the 804).
I suspect that most other people that have heard the 2 side by side will say the same. The mid driver on the 804 is a very different driver than the mid/bass driver on the 805. I heard a more recessed or veiled midrange with the 804. I really wanted to like the 804 better, but ultimately, I think the best overall choice would be a used pair of 805s with 1 or 2 REL Strata III subs. They are supposed to mate beautifully with the B&W Nautilus speakers.
good luck
I suspect that most other people that have heard the 2 side by side will say the same. The mid driver on the 804 is a very different driver than the mid/bass driver on the 805. I heard a more recessed or veiled midrange with the 804. I really wanted to like the 804 better, but ultimately, I think the best overall choice would be a used pair of 805s with 1 or 2 REL Strata III subs. They are supposed to mate beautifully with the B&W Nautilus speakers.
good luck