Hi heat - low driver control - not as dynamic at lower volumes as others - transparent but there are more transparent - but so well rounded and as a whole they are great but I do wish they grabbed ahold of the drivers a little better but that’s part of the give and take with the lush sound so it is what it is but still would like better control. I’ve owned Aleph 3, 5, J, 30, F2, F2J, J2, 150.5, 350.5, 250.8, 160.8 and prob few others I forget. They were all great. Best sounding - no doubt there - the F2J is best sounding - you just need the correct speaker for it but it’s so pure and perfect. If he could ever get that sound into 100watts he could charge what he wanted for it.