A (much) better clock does wonders. The same applies to (i) proper isolation - in my case Halcyonics/Accurion active magnetic devices -, (ii) top of the line pc (in my case the Tidal pc's I wrote about elsewhere on WBF) and (iii) (of course) three Shun Mook feet. With all this the Zanden combo is a 'killer' player, Ked.
That has been my experience as well. i have changed all the power supply tubes to Mullards from Brent Jessee at his specific recommendation (1950/60s vintage is what he sent). And Amperex 7308 signal tube. My isolation is that each box is in its own 'isolation sandwich' with HRS/Stillpoints underneath and HRS, Artesania and Stillpoints on top...plus mass damping on the transport. Each one also has some Entreq Wraps as well around digital and power cables and umbilicals.
A Distributor who came to visit and had heard a reviewer's 4-box Zanden had said there was a significant improvement with these changes, in particular to bass power, snap and transient speed. It does house music well now, whereas when i first got it, it was quite a softish sounding bass/snap. And yet these changes have only allowed the organic, sweet intensity of the Zanden to come forth stronger. changing that was an absolutely 'no go' for me, and it took months to setup the Zanden the way it is today.
And i have not changed my clock to a special one the way some have.
I think the one area where the Zanden is better than most, comparable to some, but not leading is in absolute detail retrieval of every last iota. I [think] the DCS Vivaldi is superior in this regard.