It is interesting if they've genuinely solved what must be a nightmare sealing problem at the cylinder and head interface - while keeping rubbing friction within bounds not to mention oil consumption. No amount of trying has achieved that as yet - hence the poppet valve endures.
C43 AMG, 96 Jeep Cherokee 2.5, Triumph Explorer and Thruxton
Watching the video, noticed all those other Youtube videos displayed the right of the screen... even more wizardry!
Nothing as awesome as a deltic yet though, I'm still trying to work out how to put one in my car!