Thoughts on pairing a c46 with mc402/b&w 803d?

I wish I had that direct comparison. I heard the 803D's at a dealer when they first came out and I liked what I heard, but I opted for the 802D's and I never did get them to sound great (in my room), including (later) using McIntosh MC402/C46; I have always wished I went with the 803D's, as I think they would have worked with my room better.
While the new B&W's are said to be easier to drive, they are still known to like a lot of power/current. There may be better amps out there to take control of those speakers, I may be wrong. My 30w integrated seems to have more authority than my MC402 did.

Dwmdc: At the risk of providing you with information that is not completely on point, I run a pair of 803s's with an mC402/c45 and get good results. I believe the C45 and C46 are fairly similar sonically in a two channel system with the respective filters switched out. The 402 has plenty of power left over. Although the 803d is slightly harder to drive than the s due to the additional low end driver, it should not be an issue. I was looking across the 803 - 802 range and the 402 drove the 802D's with no problem in numerous tests reaching peak spl levels of 110 db - a level right at the brink of destruction for this type of speaker - at least if sustained for more than a minimum period of time. As to sound - the b&w sound is going to swamp out the differences in most amplifiers (unless you go to a really 'tubey' (i.e. poorly designed) tube amp.) In my opinion the filter options of the c46 is a nice feature - while there are many recordings out there that sound good at hi spl's and need no filtering, there are also those that can benefit from the addition of preamp filters.