Next step after B&W 802D

I had the B&W 802 (non diamond) and went to the Wilson Sophia 2. The Sophia 2 is a great speaker. I'm now using Dynaudio C2 but I still prefer the Sophia to the C2 and the B&W 802. Agree with Bar81, see what you want to improve on. I wanted to improve on the bass and I couldn't get Bass from the B&W 802 because I was on the 2nd floor with cheap floor boards and I think the downward firing bass just went down stairs. My friend put them on concrete and they sounded completely different with much better bass.

With your amp, its not enough to drive the N802 as many here aired out.
I think your amp would work better with the Sophia 2 Or get one of those solid state amp from Accuphase and it will drive your N802 well.

Maybe you should try (more?)room treatments at the 1st reflection points before changing any components. Those bare walls(pic have got to seriously affect imaging, soundstage, clarity, etc.

Proper treatment might even raise the performance of your system, overall, to the point that a speaker change is not necessary.

it's because he uses Bose 901's as a reference.

Give a listen to the Vandersteen 5A's. They are easier to drive, can be tuned to your room, and sounds much better.