With all due respect, I would point out that those who have built-in Hexfred rectification cannot even try 5-volt tube rectifiers in a GOTL. And thus, it is impossible for them to know if they might in fact prefer vacuum tube rectification. Whereas, those of us who use 5-volt rectifiers can also use one of Glenn's Hexfred plug-ins, and therefore, we can directly compare Hexfred to tube. So it might be more valid to ask those who use tube rectifiers in the GOTL if any of us would complain if that ability was taken away. And I am willing to be the first to go on record: I can not imagine being limited to using only the plug-in Hexfred. No way! Now don't get me wrong... the Hexfred is a very fine rectifier. And I freely admit that chasing after tube rectifiers can be a very slippery slope. But losing the ability to use tube rectifiers as precision tone controls is a wonderful luxury that I would be very loathe to give up. But of course, my ears and my gear.... YMMV.