Well, I am loving Zinc and I could easily see me using it regularly. It does require a lot of modifications to suit my workflow which Zorin OS does not require, though it includes several modifications I make to Zorin OS.
It balances out to where setting up Zinc to suit me is slightly more work than setting up Zorin OS to suit me. Zorin OS is assembled in a way that the user is able to "right click > configure" in a very straightforward manner. Whereas Zinc requires you to get into the gears a bit more.
Zinc is newer, so is more up to date. It is using XFCE 4.18. But Zorin OS 17 is not far off and may use 4.18, as well. And by its release, many bugs may be worked out.
I cannot see it as a replacement for Zorin OS, but a very viable alternative to it. It comes with a lot of preconfigured things that Zorin OS does not. I could see this as being overwhelming or even off-putting to some new Linux users.
I am very impressed, as always, with teejee's insight and development.