JJ sells 2 different KT88 tubes a clear glass and a blue glass , $60 and $70 per tube, respectively. If as you stated the "McIntosh" tubes are made by JJ and cost $120 you have to ask yourself what is "special" about these tubes given that JJ doesn’t sell a higher line of KT88s under its own brand. I’d suppose that McIntosh might claim they are the best of the best, or made to their specifications. Up to you if you would buy into either possible contention at 100% mark-up over their actual lineup. Personally, all that I use JJ manufacturer supplied tubes for is amp break-in. There’s nothing SQ wise about their KT88s, 12x7s, or 5AR4 rectifiers that are satisfying to my ears regardless of the amps in play. The Gold Lion KT88 I find to be a better all around sounding tube , and very reliable. I have also used the Psvane T2 KT88 which for me adds a bit more body to the sound than the Gold Lion, but I have had mixed results with their reliability. Psvane has some new models out which I don’t have any experience with SQ or reliability wise. New production Mullard KT88, and Telefunken Black Diamonds have some good reviews if you want to maybe research them; again I don’t have experience with them.