Opinions: Martin Logan Renaissance 15a vs. Bowers & Wilkins 800D3

@farne230 should be fine.  

I would pick whatever sounds best to me. 
 

But if I had to “blind” buy it, my choice would be the B&Ws. With the right electronics in the right room they would be the better speakers. Better bass integration, more lively top end, more engaging presentation, easier with placement. 
One other downside of ML is panel maintenance. Depending on how long you plan to keep the speakers, dust accumulation on panels degrades the sound. Most of the time periodically vacuuming the panels would restore it though. 

Neutral electronics, may be even slightly leaning towards warmer side of neutral. I had good experience with Pass Labs and Audio Research with the older 800 series. They’ll need a big amp. Avoid anything bright…components or cables. 

@farne230 if you’re going the CD player route I would suggest a player with a USB input. Audio Research, Luxman and Marantz come to mind. You can then get a dedicated streamer without a built in DAC and run its usb out into the usb in of the cd player to utilize its internal DAC. Unless of course you want to add a separate DAC and transport. Lots of options to explore.