Okay I got my feet wet and opened up the E11. My first impression as this is my first Amp, overall sound improved with the Mac Book and the A900x, it sounds fuller and richer I enjoy the SQ more. The USB charge as u know doesn't work at the same time your listening.
Then I tried it with the GR07 MKll and the Samsung 3 at first I thought their wasn't much improvement, then I checked for better sound volume which I got and need a little for a busy gym. Wow I wasn't ready for the A900x to improve very nice! Now I haven't received the HD650 yet for a test drive. I did see a good deal for the E09K but like u said I really my not need it. The pricing on the E17 is kind of standard, I may spend a little more, but get a good deal if I buy both. I feel I'm on a nice track to having a great set up. Thanks to you and Evshrug.