I picked up the E18 about three weeks ago when it was still available through Amazon. So far I love it. I use it mainly as a portable DAC/AMP for my Note 2 although it works great with the PC too.
I have the V-Moda M-80s, TDK BA200s, and Sennheiser HD598. The E18 with bass boost really improved the BA200s for me. I love them but they just aren't much fun. The E18's bass boost fixed that for me. The HD598 really came alive with the E18. Everything I have can be driven by the phone alone but the HD598s really seem weak compared to when I am using the E18. I travel a lot so the battery function is a nice plus too.