The only tube in this entire list that I did not like was the Sylvania in last place. Which is super interesting because other people swear by this tube and consider it to be their absolute favorite. I guess it just goes to show that we all listen very differently and have different priorities when it comes to what we like. For me this tube just sounds inauthentic in a cartoonish way. Instruments just never sounded real. The only thing that really holds back the other Sylvanias, especially the ladder plate, was that they were simply outclassed by the tubes at the top of the list when it came to sheer resolution. The grey roundplate has it but it's a dead fish in terms of dynamics. The black ladder plate has the dynamics but it just doesn't have the low level detail and texture retrieval of the best tubes in the group.
Thanks for at least making me feel like i'm not crazy in this line of thinking about the Sylvanias. I felt both round plate versions were lifeless, regardless of the power tube pairing (@therremans - I gave it a legit shot even with the 5998 - still same result for me), and the ladder plate was just lacking in detail/resolution compared to the Raytheons.
I essentially sold off all my Sylvanias. Kept the Raytheons and GEC L63. I haven't had the pleasure of trying the tung-sols, but i'm quite satisfied with what I have for sure.
Really appreciate your monpolisation of the thread as well - definitely eye opening and many will benefit from your impressions.