I haven't gotten a multiwave yet, but here's what I hear about multiwave and heat. It does indeed make the powerplant run hotter (especially the 300, not so much the 600). The multiwave option also allows you to adjust the output voltage. According to Paul McGowan, the most RMS meters will underestimate the voltage of the multiwave. So if the meter reads 115V, it's really about 118-9V (I can't remember the exact numbers -- find it on one of the various PS audio forums). You can mitigate the heat problems by lowering the output voltage.
