Starta, Yahgan, Solidteknics, and Darto?

I'm looking at the 4 brands above to replace some cast iron.

Yahgan is very interesting since it's a nitrate carbon. And at this time, only one size.

Strata may be, I know they will soon have a nitrate wok, but I'm not sure if the fry pans are straight carbon steel or also nitrated. The lightest of the bunch.

Solidteknics while not listed as carbon steel seems to be carbon if not very close to it. Also very expensive, at least compared to the others here.

Darto is the least expensive, though I'm not sure what the duty will be in the USA.

I've seen a few YouTube vids, so I have checked there.

If anyone has direct experience with any of these I'd like to hear what you have to say.