Aball summed it up nicely.
My favorite tubes were vintage Telefunken 12AX7 smoothplates however, new matched goldpin EH 12AX7s performed admirably, at one tenth the cost. (I tried around a dozen different tubes)
Since you ask specifically. PRAT may have been its only glaring short coming and maybe a bit of top end clarity. Not a lack of air, just the minutia contained herein.
My favorite tubes were vintage Telefunken 12AX7 smoothplates however, new matched goldpin EH 12AX7s performed admirably, at one tenth the cost. (I tried around a dozen different tubes)
Since you ask specifically. PRAT may have been its only glaring short coming and maybe a bit of top end clarity. Not a lack of air, just the minutia contained herein.