Winged C's are my choice also. I prefer them over Sovtek, JJ, Shuguang, and VAC original tubes. I purchased two sets from www.tubesandmore.com. One regular set, and one set that had been cryoed and burned in. I didn't perform a direct comparison between the cyro and non cryo, so I can't tell you if they are worth the extra money but the amp sounds great with the cryo set.