The #3 post in this thread basically says the same thing in comparing the Lyr to the PS II as what they told you on the Mad Dogs thread Kamahkahah.
My Horizon and Beyer DT880 combo will make my ears bleed before I run out of headroom but then they aren't planar headphones. Although I've never heard planar headphones, I know they like power. My Magnepan MMG's are planar speakers and I know they will take all the power I can give them and still handle more. I once bridged a couple amps together to power just one of my speakers. I think it was more than 400 watts I was dumping into them and they seemed to have no problem handling it. I've read of people hooking there T50RP's (or other planar headphones) into speaker amps and liking the sound a lot. http://www.head-fi.org/t/614134/is-it-true-that-modded-t50rps-specifically-lffs-paradox-mod-is-comparable-to-high-end-headphones-such-as-the-lcd2/270
After what I've heard, I would probably gamble on the Ember as the best match for planar headphones with the large amount of power it'll have.