If you're going to spend $46 per tube, then I would try some of the NOS tubes that Upscale Audio or tctubes offer. I didn't find the Genalex anything special, and the ones I had were not very quiet. However, this sort of thing is very circuit dependent.
I've been breaking in a quartet of current production JJ E88CC tubes in my BAT 3iX. These have excellent top and bottom extension and a colorful midrange.
I've been breaking in a quartet of current production JJ E88CC tubes in my BAT 3iX. These have excellent top and bottom extension and a colorful midrange.