I do publish my webcomic on The Duck, actually I learnt of The Duck before I learnt of Comic Fury (though I learnt of both in 2019, so recently).
Personally I like The Duck and there are various webcomics I follow there, although there is some overlapping with webcomics published here.
There is some limited customization possible for comics, but not as much as here.
The forums seem dead.
I have more readers on The Duck than here (judging on the number of pages read, not on followers), though I was featured some time ago and I also advertised a bit on the site so it isn't really comparable.
They have a sort of daily blog that sometimes is interesting (depending on personal interests of course).
On the whole I think it's worth a shot for mirroring.
Reapeageddon:I've heard of the site before, and I'm quite intrigued. Is it worth it to create a mirror of my webcomic there?
Maybe! When it comes to mirrors you never know what new people may find your webcomic intriguing. But you know that's just the same as posting on twitter, Instagram, deviantart or any other free host site with hashtags.