I've been buying from Brent for years, and yes, he does make great recommendations.
I've used every type of Sylvania 6SN7 except the metal base. Currently, I have WWII VT-231's and 6SN7GT 3-holes in my amp. The VT-231 is milspec and presents a transparent wide, 3D soundstage. These tubes have become very expensive. The GT is more dynamic with smooth extended highs and a deep low-end. All Sylvanias present a sense of realism.
I'd like to buy more VT-231's (they're so quiet and clear) but I'm waiting for the Linlai's to arrive.