Just got my e80 in today and right away I know I've found the sound signature that I've been looking for! Neutral with great extension down low and high without sibilance. And unlike the Re-400, it doesn't have the murky warmth feel to the sound that irked me. It's just clean, clear and resolving (pretty darn good for its price but I don't know how resolving it is compared to IEMs above the $200 price bracket).
Compared to Dunu Titan 1, the e80 is truly a competitor sound quality wise as they are rather similar. Titan 1 sounds a little more detailed due to the extended and sharper shimmery treble. And of course the e80 isolates so much better. Titan 1's soundstage is more out of the head and expansive but the e80 is more intimate, like my EPH-100. One thing I do dislike about the e80 is the cable; if it was like the Titan 1, it would've been perfect for me. I also found the tips provided to be of poorer quality, being rather thin and soft and some are deformed due to being squeezed in the packaging.
Another little plus point is that I can actually wear them in bed and sleep in any position I want! I was quite surprised as I'm actually using the double flange tip (the only tip that seals my right ear properly). All in all, I'm very well pleased with this little purchase and I won't be buying anymore IEM until my EPH-100 dies. Then maybe I'll get the Fidue A73 to replace them.
How is the bass and sub-bass compared to the RE-400? I found the RE-400 too boring for pop and EDM.