B&W 800D vs 800 Diamond

Also I do have the same filling with the B&W 803 diamond. Like the blanket is over the speakers or I am listening from another room. I can not stand the sound . Terrible.

Not in my experience - I have been listening to my 803Diamond the whole day - crystal clear open sound.
The trick is careful system setup. And careful component selection (not necessarily expensive gear, but good quality gear) because the Diamond series is very transparent to front-end performance - more so than the previous 80xD series.
I will add that the midrange (which is very good) does not reach standard of the diamond tweeter (absolutely exceptional) or the excellent rohacell woofers. In the previous 80xD I noticed some mild chestiness on the occasional male vocalist, but not on the latest Diamond series which surprised me (because I thought this was an artefact of the FST midrange, but it turned out to be, I guess, due to the previous woofer and/or crossover design).

The following reviews describe the differences:

http://hometheaterreview.com/bowers-wilkins-800-series-diamond-800-diamond-loudspeaker-reviewed/

http://www.stereophile.com/content/bampw-800-diamond-loudspeaker

http://www.audiovideo2day.eu/en/article/10402/Bowers-Wilkins-800-Series-Diamond

I wondered this also just before I purchased a used pair of 802D2 so I called B&W. BTW, these guys are so nice. They research things for you like how much did things retail for then. I asked them to compare like 6 speakers. The were Johnny-on-the-spot. 
Here is what they told me. They said the D stands for diamond in all of the models that have a number then a D. They may have come out with different models of 802D but they are all diamonds. The 802d that I purchased have a chrome ring on the tweeters. B&W were able to identify them as 802 Diamond 2

 

i hole this helps. If you are unconvinced just call them. They are wonderful people

* I hope