I think I said this before, but I found the Psvane 6NS7-type tube to be the best in a Pinnacle (over lots of NOS vintage tubes I tried from all the well known names),
with the sweetest extended highs and the most transparent bass, very controlled, and that great inner-light that I associate with tubes in general.
So Psvane would by my 1st choice to try for any tube type. My first one lasted about 18 months of pretty heavy use before they got noisy and had to be replaced.
Seems like good reliability to me.