As Dakkon mentions, buying a good, reputable power supply now means never having to replace it so long as you take good care of it (usually). Therefore if you're going to go this route, I would personally get the 200 wpc minimum so that later on you don't get the itch to upgrade it. Then once the technology changes you can upgrade your processor, without having to rebuy the power amps that come in standard recievers. Imo power amps don't gét upgraded in standard recievers, so why pay to repurchase those same power supplies everytime you need to upgrade your reciever?
At lower levels you won't find much difference in SQ, that comes (as you suspected) when the volume knob goes up. Don't get the wrong impression when Quack says 'only 3 dbs'... 3 db's is a HUGE difference! Before I bought the XPA-3, my Denon (volume went from -70 up to +12) hit my maximum comfort volume level at about 0. Once I hooked the Emotiva up, it hit that level at around - 18.
