Audioquest Water XLR Interconnects

HI Pony - it's true that Quadlink had a LOT of warm fuzzy bass, however, it was NOT pitch accurate and was out of proportion to the rest of the frequency range as the upper end was also a bit rolled off.  Now the AQ dos system is a good thing, BUT - it does NOT break in the cables.  All it does is to burnish the dialectic to keep it from absorbing and releasing sound randomly.  Your cables will need to run for around 40 hours for a 1M pair to sound their best.  Give 'em a little time - it will be worth it!

You sound surprised that different cables would sound different. They do, and that's what you're hearing.  You do need to let the cables break in for a while before making any final judgments.  I usually mark my calendar for a month with new cables and try to reserve judgment until then.  But it's also possible that you just prefer the Cardas to the AQ.  The older Cardas was known for a warmer sound and often used to tame a bright system.  Unfortunately, many audiophiles claim they want a Ferrari, but really want a Bentley.  They think they want to feel every bump and hear an engine roaring behind their heads, but they really want a relaxed quiet ride.  Both cars are magnificent, but don't buy one if you want the other. 
But do give the AQ's a chance and they may surprise you down the road.  Or not.  That's the way this hobby goes sometimes.  In old days, we went to the audio stores and listened before we bought.  Now we buy on the internet based on reviews by people who don't even play music on their You Tube channels, not that that would help.  So best of luck and I hope you will be happy with your new purchase down the road.  And if not, you will have at least learned something.  Hopefully. 

Does anyone know if the B&W 802d (first generation) were considered a bright speaker?

@onehorsepony, I sold B&W for over 10 years, and yes the 802D's were bright and some what aggressive. I've never been a fan of B&W, highly overrated speaker.

Would anyone suggest unbalanced from cdplayer to preamp, then balanced from preamp to power amps?

Or, stay balanced throughout?