That's a matter of opinion, and as far as I'm concerned not true. I'm sure Schiit tried a lot of tubes and found something that was both good, plentiful, and cost effective. I took the Saga over to a friend who has a stockpile of different new and vintage 6SN7 tubes. After trying half a dozen (some better than others) it was a pleasant surprise to come back to the Russian stock tube. While perhaps a little more aggressive than the others (at least with speakers), it had a liveliness and punch that made music fun and engaging. While I'd be open to listening to more tubes on the off chance I find something preferable, I don't particularly feel the need to "upgrade".