It will be depends on your system set up and your music taste.
I have tried many different 300B tubes(AVVT, KR 300BXLS, JJ Tesla, Svetlana, EH, Sophia, Cetron, Valve Art, Sovtek) in my system(Cary 300B SE monoblocks were used in comparason). In my system and music I listen to(mostly Jazz and Classical in vinyls), AVVT(C37 glass) sounds better than WE 300B in my taste. WE300B(new production) definitely had sweeter midrange(initially my top pick was WE300B) than all others but trading off highs and lack of bass control compared to some of other tubes. KR 300BXLS definitely had most authority and best bass. AVVT and Sophia(mesh) had better details than WE300B but not losing too much of midrange magic of WE300B. AVVT(C37 glass) sounded more of somewhat balance of WE300B midrange and KR 300BXLS bass with details. I have seen/read some people describing AVVT 300B tubes as being bright but I do not think it is the case in my system, I really love the details.
I only have used new production WE300Bs and not sure how NOS WE300B would measure against rest of the field.