Yeah I’ve seen that and similar videos before. It’s usually the main advertising point for the ck gas saver kits but in reality regarding actual performance anything with a gas lens type set up or defuser or both are pretty much equal in regards to delivery performance.
The bigger cups will offer a better coverage for obvious reasons but the principle of the actual gas delivery is no different to a conventional gas lens with a no 7 plonked on it.
I like ck lenses. They have never let me down. I bought a big cup the other day as I’m being asked more and more to do little Ti jobs. I went with a set up from a new company on the block called Edge.
Tested the cup and it certainly does what it’s supposed to do but it’s sill the ck lens doing the main delivery, the cup just expands the coverage area. You also need much higher flow rates through big cups. Wasted really on anything that doesn’t actually need it.
As Richard said, I have gas lenses and to be honest you can do without them 95% of the time and still get decent welds...I would only use them diffusers when welding titanium or very exotic metals...