i prefer the etherregen (and outboard clock) to handle the incoming ethernet feed personally, it is what i settled on after trying the eno and muon... it is more boxes and power supplies and so on, but to my ear the sound is purer
Placing a Network Acoustics Muon Pro Ethernet filter and cable (Streaming Pro) has yielded a much more organic and less shouty (harsh) sound.....I cannot recommend the Streaming Pro high enough…
2 equally valid yet contrasting options, which suggests one must try on their own to find out if it works in ones system. I like the first answer though, that helps me to put the Muon lower on the "things to try list" that resides in my head.
Like others have mentioned though, I don't think a software update should change your presentation that radically; the first thing I would do is research other forums to see if others with the ZENith mk3 have experienced the same?