I think it would be difficult to differentiate in a listening test.
However, the Discrete amplifier could potentially be more dynamic. Discrete designs are generally considered superior as they use (usually) higher grade components. Discrete is usually preferred.
As far as "warmth" and other things go most of that is waived goodbye when a simple blind test is done. (meaning voltage impedance and level are all kept in check) Some people claim to hear these things, but usually their comparisons are flawed and not equal. if there would be any difference in this instance, like stated before, it would most likely be dynamics.