Top Luxman integrated - 509u or 590Aii?

The Luxman integrated amps are highly regarded. Their two top models are similarly priced, though they differ in that the 590Aii is 30 wpc pure class A, and the 509u is 120 wpc class AB.

The class A 590Aii amps are supposed to sound great, but they run very hot and are inefficient.

The class AB 509u amps are powerful and more efficient, and they also apparently sound good.

I have auditioned the 550Aii (20 wpc pure class A), and it sounded wonderful. It is the only Luxman integrated on display in my city.

I am confused as to which would be the better choice, the 509u or the 590Aii?

Regards,

Mark