802 diamonds with class d amp

I listend to the D as well. Because depth was still poor I did not want to go further with B&W. B&W shopkeepers tell the same story. I want to play far behind and even beside the spakers. B&W is still very poor in this area. In the absolute sound this is a pre. Without a 3 dimensional deep and wide stage you are in the 2 dimensional league. @ dimensional audio= standard audio. Because a cheap amp does play at the same way. I played a few times with my own recordings with 802D and new Classe gear. Mannnnn depth was soooo poor.

I can't speak to class D amp options having no familiarity with them. I have B&W 804 Diamonds (the current 2nd gen) and use Musical Fidelity's M6PRE (class A) and M6PRX (class A/B, 260w dual mono) which pair nicely with 804 Diamonds and didn't put me in debtor's prison. MF makes an M6 500w integrated that lists new for $7000. I suspect it would work well with 802 Diamonds. There are a couple of M6 500i demo units listed on Agon right now both under $5k. Just a thought. I have no connection with either seller.

I don't seem to have the depth issue you indicate. What sound differences will I notice with a better amp?

You first have to understand what the differences are between the talents/properties of a Rotel and a Pass Labs for example. Also the difference between how wide and deep a speaker can make the stage. Because B&W does not make crossovers what can give you an exeptional deep and wide stage. Like Musical Fidelity ( I owned it, sold it for a long time and I even did audio shows for Musical Fidelity) is not very good at giving a deep stage. There is only a little of depth. Every brand even if you are talking about an amp, source or speaker have there own properties/talents. There is a very big difference in how the stage is projected between all these brands.

With the B&W and Musical Fidelity components that I'm using and given their price points, soundstage width and depth is acceptable but definitely not exceptional. For me, the ability to reproduce the sound of different instruments with realism and clarity across high, mid, and low frequencies is a more important consideration than soundstage width and depth. In these areas the B&W and MF components I'm using are exceptional given their price points. Certainly if I could afford Pass Labs amplification, I'd be waving goodbye to MF and using something else.