Genelex KT-66 v Chinese KT-66 Retros

Anyone heard either or both of these tube in a modern audio amp( in contrast to a guitar amp)? The buzz is that the Chinese Retros LOOK and SOUND like the original Genelex KT-66's. Truth, Close but no cigar or NOT!! Your impressions would be greatly appreciated.
Thanks for your advice, John. Were the Chinese EL34's early production or Chinese tubes from a while back? I've heard that more recently the Chinese tube quality control has improved. Thanks again. Bill
Hi I actually own some of each. The Chinese tubes sound fine, and I am hard pressed to hear the difference if there is one. I use Quad amps. The build quality and long-term reliability scare me, though. A friend had Chinese EL 34's in his Dyna ST 70 and one shorted with no warning and took out some resistors.My tehnician , who has been servicing tube equipment since the 60's, said that this occurance is rather common with Chinese tubes. John