A very thoughtful and thorough reply - my response isn't going to be anything like as useful. I've tried a few different Treet carbon blades (there are even more than @pjgh mentions on the market), and despite really liking all their stainless blades (that I've tried - Platinum, 7 Days, and to a lesser extent Trig), I've yet to really like any of their carbon offerings. But all were better than the Flying Eagle carbon blade that I once tried, and I've heard bad things about the Bangladeshi carbon blades you can find.Yep! Just recently, in fact: https://www.theshavingroom.co.uk/community/index.php?threads/in-praise-of-treet-dura-sharp.52209/
The Treet DuraSharp is indeed a carbon blade but with the edges treated (Treet'd?) in a similar manner to stainless. The net effect is a carbon blade that doesn't readily get rust spots during the workable life of the blade. I found it gave four lovely shaves and would have gone to five for me, I'm sure. My normal is 3, so adjust accordingly.
Treet also have the Classic, Black Beauty and Silver as carbon blades. To my face, the jury is still out on the Silver as I'm struggling to figure just where it sits in the line-up (more on that in a minute). The Black Beauty is the same grind as the DuraSharp but the edges are not treated and the blade is black. It gets very mixed reviews and is empirically quite dull. That said, some folks (myself included) do like the shave. I've yet to try a proper Classic.
Back to the Treet Silver and a slight hop across to the Treet 7 Days Platinum. I commented that the Treet 7 Days Platinum (a stainless blade, by the way) did not supplant the regular Platinum despite being smoother and lasting longer, because it feels different - it feels like a Russian blade where the regular Treet Platinum does not. And on that, I'd say the same about the Treet Silver - it's a carbon blade, treated and coated, and unlike the Treet DuraSharp also feels like a Russian blade. The Treet DuraSharp does not.
Another thought. More recently, I tried a Shark Super Stainless for the first time and commented on how primitive it felt, like driving a car without power steering you can feel everything it does. Final thoughts on that blade was: if the Treet DuraSharp is a carbon blade pretending to be stainless, the Shark Super Stainless is a stainless blade pretending to be carbon. It's not a blade for everyone.
Long and short of it ... yes, try the Treet DuraSharp. For an introduction to carbon blades, it's lovely!
I have both blades and I will give them a go to find out if one is different to the other.I tried to buy more Durasharps a while a go & Treet advised that they had discontinued these & just offer the Classic carbon style now. They assure me that these are the same as the Durasharp, hopefully a regular user can confirm that at some point.
Finest packaging of any modern blade! Saying that there is a vintage blade with that artwork, I saw it on Ebay.I think the difficulty with Trig is perhaps that it is the niche end of a niche manufacturer. I have used one, but don't recall it as remarkable, where I have indeed remarked on how good Treet blades are.
Funnily enough, here's what I thought was a vintage blade although the blade itself looks quite modern ... Super Stainless! Maybe they'll just bring this back.
The Trig Silver Edge shaves a bit like a Astra SP with a few shaves under the belt, it's a smooth blade and performs well but doesn't last very long.Like LORD, Treet make various types of blade & many more packaging styles for each type. Also when my TRIG run out I am advised that these will change to Durasharp Stainless, just to confuse matters further. I may not restock though, TRIG are not very popular.