Very true, but once again, if you don´t know how to measure impedance rise or it´s first time you heared about it, then you are not the guy to wire your amp to 0.5 ohms, if you have voltage drops or even setting it all clipped and with gains cranked up, we all know what´s gonna happen!!!
Also, yes, you can use impedance rise on your favor and wire your amp lower, but there´s simply some amps that just don´t like to be wired @ 0.5 ohms even if you have major rises, myself, i only wire amps below 1 ohm for burps, but once again, i´ve never used strong amps like sundown for example, this is latin america, over here you find cheaper amps only hehe, biggest amp i´ve ever had it´s the SD and there´s no reason for me to wire it below 1 ohm because my subs reach mechanical capacity about 30% of my amp capacity hehe, i bought it just thinking on the future, hell, i don´t even know why i´m talking about me hahaha,sorry for the off topic, yes impedance rise is a bitch and yes, Soundigital rules!!! hehehhe,cheers...