Mksr, the Duettes are indeed much better than the 805Ds. Also, as Onhw61 has mentioned, for music you would not need a sub in your room with them. Though, I do not know how much bass they put out when they play music at lower volumes (when cracked up they put out enough bass for most people).
If you can stretch it, my advise would be to get the Wilson instead of the B&W 805Ds. Not only you have heard how much better they are than the 805s (which will hunt you for a long time if you would buy the 805s), but I assume that half the price of the Duettes 2 is not that much more that the price you would pay for the 805Ds plus a decent sub. However, as before, I advise you to try them in your room to make sure they will not overwhelm it with bass. Since Wilson dealers are required by Wilson to set up every pair of Wilson they sell in their client's room (at least that is the case here in Europe) maybe you can reach an understanding with your dealer, i.e. that you will buy the speakers if, when set up by him, they do not overwhelm your room.
If you can stretch it, my advise would be to get the Wilson instead of the B&W 805Ds. Not only you have heard how much better they are than the 805s (which will hunt you for a long time if you would buy the 805s), but I assume that half the price of the Duettes 2 is not that much more that the price you would pay for the 805Ds plus a decent sub. However, as before, I advise you to try them in your room to make sure they will not overwhelm it with bass. Since Wilson dealers are required by Wilson to set up every pair of Wilson they sell in their client's room (at least that is the case here in Europe) maybe you can reach an understanding with your dealer, i.e. that you will buy the speakers if, when set up by him, they do not overwhelm your room.