I'd actually prefer upgrading to the 804S over adding a sub, but I haven't had much experience with subs and the little I have had wasn't great.
The advantages of stand mount speakers, usually, is their ability to disppear, at least better than floor standing speakers.
I have only heard the 804S once and I liked it; having owned the Signature 805 I felt the 804S reminded me of the Sig 805's with added weight; I also have a friend that has 804S speakers and is very pleased, he also owned the Sig 805's with a sub, he prefers the 804S.
Brian
The advantages of stand mount speakers, usually, is their ability to disppear, at least better than floor standing speakers.
I have only heard the 804S once and I liked it; having owned the Signature 805 I felt the 804S reminded me of the Sig 805's with added weight; I also have a friend that has 804S speakers and is very pleased, he also owned the Sig 805's with a sub, he prefers the 804S.
Brian