Here is one of the first E18 owners.
I visited FiiO at the Hong Kong Electronics fair a few days ago and bought myself a E18.
Awesome little thing.
I have a Samsung Galaxy S3 Android 4.1.2 with Boeffla Kernel. When I connect the FiiO E18 it takes a few seconds and it works flawlessly right away.
Does it sound great ? Yes
How does it sound compared to the Galaxy S3 (optimized Boeffla Kernel): The sound is faster and much more detailed. It sounds quite transparent and punchy, resolution is quite superior.
I use Poweramp and Neutron music players on my phone and good news is that both app's Equalizers do work even when listening via the E18. Only kernel EQs and other sound tweaks within the phone's kernel are bypassed.
I have not had the time to try all the other features of the E18 yet but all I can say is that I liked the E18 right from the start.
If you have any questions regarding the FiiO E18 I can try to answer them from an end user's standpoint.
Btw. I have never owned any of the other FiiO devices so I cannot compare the sound quality/signature to other FiiO products.
Guenther