Stainless steel? I can understand wanting to get away from soldering, what with the EU having to comply with RHOS...but why introduce galvanic corrosion and requiring folks to use inhibitors in their cooling loops? I don't care how stainless the steel is, it will still oxidize-reduce with the copper in your loop using your fluid as the medium, like a battery, and the precipitates will end up in your loop, most likely as a sludge.
But...if it honestly gives 3x performance, I might look at it. I'm not sold that round tubes are better than flat for heat dissipation, though, unless they are inducing turbulence. Laminar flow would have the water on the edges cooled, while the water flowing in the middle of the tube remains uncooled. With flat tubes, that uncooled portion is small, while with round tubes, it is much bigger. By adding turbulence, you force the water away from laminar flow and more water meets the edges. To do this, though, you have to introduce impingement, which means you need more head pressure from your pump, which dumps more heat into the loop.
It will be interesting to see some real test data for this new product. And we won't know any real-world results from galvanic corrosion testing until it's been in use for a while. Age-testing on a product this new...yep, hate to be the consumer who does this for the company. But, if the corrosion is very slow, then flushing your loop every six months might be enough to save it, along with inhibitors. We'll see.