W4S is owned by Cullen, we could call it a division of Cullen. As for the ZP90 jitter issue the ESS chip in DAC 1 and 2 have extremely good jitter reduction. I hear very little difference with my Cullen modded ZP vs an un modded unit. Beyond that the sound quality of a ZP90 and a W4S Dac is great, add to that the functionality of Sonos and I think you'll be very happy.
