As an owner of an amp designed for the KT150, the ARC Ref 150 SE, my only comment would be why even wade into the weeds as to which is better is any particular amp when New Sensor has terrible QC in general and most terribly with the KT150? For over two years now, New Sensor has failed to make any improvements in their QC while continuing to put out KT150's to the peril of the consumer.
If you buy a quartet or octet of "matched" KT150's from virtually any source, you are doing so at your own risk. And in case I am not clear to you, I am saying that most vendors who claim to match tubes do not do so very reliably. They either lack the necessary equipment, the necessary know-how, or both.
If your amp has fail safe features such that an arcing tube will not necessitate any repairs and your supplier is willing to give you 60 days, I could see venturing into the 150 waters. Otherwise, I would stay away unless you have money to burn AND don't mind the inconvenience of taking your amp in for repairs/sending it back to the manufacturer for repairs.
If you buy a quartet or octet of "matched" KT150's from virtually any source, you are doing so at your own risk. And in case I am not clear to you, I am saying that most vendors who claim to match tubes do not do so very reliably. They either lack the necessary equipment, the necessary know-how, or both.
If your amp has fail safe features such that an arcing tube will not necessitate any repairs and your supplier is willing to give you 60 days, I could see venturing into the 150 waters. Otherwise, I would stay away unless you have money to burn AND don't mind the inconvenience of taking your amp in for repairs/sending it back to the manufacturer for repairs.