What would sound better between the Bit One and the Pioneer p99? The pioneer has just about as much tuning ability. I would think that if you were not to use the optical input of the bit one and just went with RCAs, the pioneer would have a leg up because there would be one less conversion in the chain between digital/analog. There aren't that many HU's on the market that even have optical outs, maybe they will be coming? I think the ultimate setup would be to use a deck with an optical out to a bit one to an audison Thesis amplifier. The Thesis line has optical connections so everything would stay digital until the power amp stage of the amplifier. I have no idea how much the top end Audison line costs, probably outrageous $.
Also, the new Alpine H800 has a optical in, hopefully more of there decks will have optical outs in the future. I think right now its limited to their nav units.