The original poster hasn't answered my original question about whether he already has 18 or 24 bit speakers, and I have no idea about the difference in price he's being quoted for the two.

For future proofing I'd go 24-bit 5ks. He can always move them to rears if his existing 5k rears are 18-bit. If he feels this is bass light one or a pair of D1500s can be daisy-chained off them for peanuts these days (I appreciate there are already subs in the mix).

Sooloos, Roon, G series (with LPS upgrade), 800 series (with LPS upgrade), HD621, AC200, Prime and PS, DSPs old and new.

Purdeys, Moke, Leica, 'Blad. Only the best.