[Bojamijams]

From reading around, both of these would seem to be good matches but I'm curious which one actually is better if anyone was lucky enough to hear both of them.  I also can't find the P-P voltage swing specifications on either of these headphone amps so I can't even tell which one is more 'powerful'
 

 

[Bojamijams]

I have found that the KICAS has a 10k ohm input impedance which is quite different then the usual 47k ohm (which the m-stage has).
 
I'm curious, what effect will this much lower input impedance have on the sound?