I have not heard much yet.
From the look of them they are quite a bit larger than a KT88, as seen in the same amp for size reference.


I have high hopes they will have the sonics and reliability I am looking for.
Then maybe some amp manufacturer will produce the amp I seek..namely a simple ,well executed , high quality design
with a single push pull pair per channel producing around 100 wpc , that makes no apologies to a solid state amp in regard to slam and frequency extension.
Oh, and not too expensive....
One can dream....Greg