I first tried switching to Mohawk Ultra Gloss.
It's more expensive which is a downside.
The Mohawk Ultra Gloss itself has a very perfect mirror finish surface and a good stiffness. Opacity of the 8pt is ok but not great.
Printed on my docucolor 242 in enhanced gloss mode, the Mohawk Ultra gloss might be slightly too glossy in any pure gloss areas. I don't like it better than the old kromekote c1s that was about perfect for my needs. The Mohawk Ultra Glosss also curled some in the finisher tray requiring me to remove it every so often or it would stop with a stacker full error. It collated well though, and overall was nice. If the price was the same as the old kmorekote I would probably stick with it.
However, I then tried the new Xerox Super Gloss which also changed the same time as the old kromekote was discontinued. (It was Xerox Superior Gloss C1S last year and is now Xerox Super Gloss. (again maybe) I tried a test carton and this will be my new C1s of choice.
Looking at the unprinted sheets, the Xerox Super Gloss has a mirror cast coated surface that isn't quite as perfect as the Mohawk Ultra Gloss - it has a tiny bit more scuffing when viewing from an angle the blank sheets. The Xerox Super Gloss 8pt is also slightly less stiff than the Mohawk Ultra Gloss 8pt. Opacity is about the same to my eye.
However, printed on my Docucolor 242 I find the printed result is equally good to the new Mohawk. The gloss is just right and any tiny "scuffing" in the mirror cast coating doesn't show once it's printed - I can't detect it looking very, very closely. It also stacks perfectly in the finisher tray, not that this is a huge issue, and collates fine. Overall, the pricepoint of the Xerox Super Gloss will make this my new C1s of choice.