Early production of Sophia did have issue of longevity, not lasting for more than a year. Jack did spoke to Sophia and we did get portion credit or they replace it with newer production. I have my Sophia replaced and the new one lasted me over an year before I sold it. EML are current production and they have been proved to be very good sounding tubes. EML does have longevity issue too in the early production, they have since changed just like Sophia. Unlike Sophia, I do not have any issues with both EML 274B and EML 5U4G.
5U4G - dynamic, details, and soundstage depth
274B - one word "romantic"
If you are getting tubes for WA5/LE, here are my recommendation.
Rectifier - 596 or EML 5U4G
Driver - TS 6SN7 BGRP or Brimar CV 1988
Power - EML 300B
Thanks for the notice about longevity. Why did you replace your Sophia with EML? I take it you enjoy the EML more since you recommended it at the bottom.
Have you tried the offerings from Shuguang or Psvane? What do you think of them?