I have heard it several times.
I can't imagine there being anything better out there for the price.
The Melos that this circuit is a replica of sold for $3,950., and it got lots of raves. Gary's version cuts features like a balance control, headphone jack, number of inputs, etc, but the parts quality is better and a lot more reliable.
For $450. it's a steel. It sounds too good for that price.
One of the last guys that got a demo unit posted info about it here. His views were no different than anyone else's. He loved it but did not have the money to keep it.
One of the others guys that received a demo unit called Gary and told him he was not getting it back and that he would have a $450 check in the mail the next day. He love it too.
Same goes for all the regulars from the North Texas Audiophile group. Everyone gave it a big thumbs up.
But hey, don't take my word for it. Try one out for yourself. Your only disappointment will be if you try it out but don't have the money to keep it.
Gary's budget reference pre-amp beets it easily but that pre-amp is $1,400.
There is info in my forum about it and some pics.
His reference pre-amp is the best I have heard at any price but is considerable higher at a little over 2 grand.
Highly recommended.