I agree the 30 Watts on Luxman is conservative. I am guessing the Luxman class A integrateds are under-rated due to heat sink restrictions. The 1/3 power preheat testing required may be too much, so they rated at 30 Watts.
Listening here with my 507s I can't tell I ever use more than 5. :)
Listening here with my 507s I can't tell I ever use more than 5. :)