The ZTTO post mixes some of the old and new ULT cassettes. The Goldix post has all the new ULT cassette sizes. I have both the old Goldix and ZTTO ULT cassettes, they’re essentially the same. I’d just pick whichever has the best price.
At least with the older ULT cassettes, I have no complaints.
I cannot hardlink to a selection (at least I haven't found a solution yet?!), so you gotta pick the newULT version yourself. For me it currently is about 10 USD cheaper. But yes, prices vary a lot. Often sellers increase their price on 2. day of choice day. So you usually want to be ready to pull the trigger right away.
And it's still 12g lighter than the Goldix. For some that alone might be worth getting that (no matter the price)
