I would have to say that the Nautilus' are better than the Matrix series,from my limited point of view, in so much as I heard the Martix at a friends and the Nautilus at home and on different components. This a magnum dynalab 208 reciever. Very smooth, very nice and it did it for me. I would like to add to the discussion above in that to me the 803's were more laid back and not quite as quick on its heel as the 805's. Maybe in the upper midrange where the 805's woofer starts to break up the 803's have it, but with a good sub I DID choose the 805's over the 803's when I could have taken either. The reason: I would not have to spend as much on amplification, they sounded more lively, and the extension of the 803's would not have gone lower that the 805's with a sub. If I had a much larger room I may have gotten the 803's only because they seem to do the soundstage thing a little wider, and I mean just a little, when you sit with more distance between you and the speakers.
