If he put JJ 6V6S tubes in there, I can tell you from experience they do not sound like 6V6 tubes. They are way more 6L6 like. Whether you like them or not is comes down to the individual, and what they are looking for,and perhaps even the amp they are used in can make in difference. In my TopHat amp I did not like them one bit, and couldn't yank them fast enough. But that is the only amp that I gave them a try in, so maybe, it was just the way that amp reacted to them.