802d for a 10x13 room, 8ft ceiling - am I nuts?

Oh man I just realized they got rid of the two bass driver 803s... That was a good speaker for the money and the sweat spot in the B&W line.

What is the list price on the new 804Diamond?

Yes they are way to big sound wise. The down firing ports really needs some room to breath. I would demo the 803d. Much of the same sound and a lot less money. Better speakers in the wrong room does not = better sound than "lesser" speakers in the right room.

If you must have the 802D better buy good bass traps right out the gate.

I believe one of the major problems with large speakers in small rooms is not so much the volume of the room but the fact that you can't get the speakers away from the wall.

I am very familiar with the 802D and have heard it many times in different sized rooms. I have also owned the 703s in the past and looked to upgrading to the 802D a few years ago.

802D:
I found that in large rooms where the speakers were 5 or more feet from all the wall they sounded very good and filled the room with nice balanced bass.

But I heard them in a room about the size of mine (12X20ish) and things changed. I tried three set ups in the 12X20 room.... I have a very good dealer... The first set up was pretty typical with the speakers about 3 feet off the back wall and 2 feet of the side walls. The sound was ok with this setup but bass had a few lumps and sound stage was average. Then we move the speakers to a semi near-field set up. We put the speakers in the middle of the room (10 feet off the front wall) and made an equilateral triangle about 8 feet. I sat about two feet off the back wall. WOW did they sound good, clean bass and the largest sound stage I have ever heard.

Next in the same room we moved the speakers back into the front corners of the front wall and the uneven bass was back and the sound stage compressed. The bass honked and farted at hight volumes with the speakers in the corners.

703s:
I bought these in college when I had no money.... yeah you need to eat a lot of ramen noodles in college to afford audio... Anyway the speakers were in a 15X17 foot room (rotel gear). They sounded pretty good at the time but the bass was always lacking and it needed more punch IMO. About two years later I moved into my new wife's house. We were in the process of finishing the basement so I need to put my gear somewhere... They went in a 12X10 foot room. Oh man did the sound change. They had WAY too much bass and it was one note with no texture. Luckily this set up did not last long...

I have now moved on to other brands of speakers. But my point is the room matters. But you can work around it some times. But I think with the 802D you are setting yourself up for a lot more work than going for the 803D. Try calling B&W direct and see what they say. You may be supprized how helpful the manufactures can be.