I have had several sets of 5ks both 18 bit and 96/24 factory conversions and smiley face . My experience has been very positive with all all of these.
On my very oldest 18bit 5ks,(series 1) I once had a cone replaced about 5/6 years ago . These speakers are now over 20 years old and sound seriously good. Not worth big money second -hand, but still offer startling performance
Best regards Huw
#1 52KSE, 218, Panasonic plasma, Sony Blu Ray, Humax, Yamaha sound bar.
#2 Muso 2 Panasonic TV.
#3 C15, TwinStore,MS600, Teac X1, 562v, 565, 555, 5Ks & 5KHC 18 bit & 24/96, Arcam Solo, Systemdek I920, Ortofon M520, QNAP Roon, Synthèse Floating 2.Thorens TD160 ,Ortofon SL15e, Pioneer DAT
#4 Panasonic 4K, Canton DM75.
#5 F80, MS200, iDock.