I agree with you that watts are watts no matter what the voltage is. But the key thing is that in the US you guys are limited to about 1,800W out of one of your sockets, but in Europe we can get 3,000W from one.
This might make a difference to a big muscle power amp, being able to draw a lot more power out of the wall might enable it to sound better. Might.
This might make a difference to a big muscle power amp, being able to draw a lot more power out of the wall might enable it to sound better. Might.