I am in complete agreement with Tdavism3. The Nautilus line is not the most efficient regardless of their ratings. I drove a pair of 802 Nautilus with my Electrocompaniet AW250DMB and was very happy with the results. That is until I heard the Talon's, but that is another story for another time. I don't think that any of us who have posted have really answered your question, but low powered tube amps coupled with a passive line stage driving a speaker that needs headroom to come alive is not the answer. You cannot go wrong with the Pass. Even if you didn't like it, the resale value is definetly excellent. It is also IMO a more neutral (or honest?) sounding amp than the others you mentioned. Remember, Electrocompaniet designed a pair of their best amps to drive the Nautilus 801. The same sonic signature is intact through both lines, so I think it would be a safe bet that EC & B&W are an excellent marriage.