I've just picked up my new Rotel amps. I was intending to use the 1075 for LCR + surrounds and the 1070 for the rears. Looking at the units though, the transformer in the 1075 doesn't look 2.5 times the size of the one in the 1075. Would I therefore be better off using the 1070 for front L+R and the 1075 for the rest? Or doesn't it matter?