[aeroG1]

Hello fellow head-fi addicts.
 
I've been using a vintage Denon receiver as my primary headphone amp for a while now, but it's finally starting to croak. I now have to find a replacement, I can buy used. I will be mainly amping a Sennheiser HD 565, and possibly an AKG K7XX. I currently am using a HifimeDIY Sabre DAC as my primary DAC. The Yulong U100 interests me because of both its warm DAC and Amp, and I figure that if I find it to be too warm and dark, I could swap in the Sabre into the chain to brighten up the sound.      
 
I've narrowed my search down to 2 amps; the Matrix M-stage and the Yulong U100.
This is how I could set each up:
 
For the M-Stage:
Desktop -----> Sabre DAC (via usb) -------> Matrix M-Stage ----->  Sennheiser HD 565
 
 
 
The Yulong U100 interests me because of both its warm DAC and Amp, and I figure that if I find it to be too warm and dark, I could swap in the Sabre into the chain to brighten up the sound:      
 
Desktop -----> Yulong U100 (via usb) ----->  Sennheiser HD 565
or
Desktop -----> Sabre DAC (via usb) -------> Yulong U100 (via line-in) ----->  Sennheiser HD 565
 
 
There's someone selling the Yulong U100 for a great price new right now, here on Head-fi. I'm debating about snagging it, but the
M-Stage also shows up around here and it is widely regarded as one of the greatest sounding amps under $500, and it is said to pair magically with the AKG K700 series, which I plan on getting a pair of sometime in the future, hence my hesitation. 
 
So now I turn to you, fellow head-fi addicts. For your advice and thoughts. Please shower me with your wisdom.