Ok, I got out of lecture an hour early. Let's go!!
Please bear in mind that these impressions are the result of what I'm hearing from directly A/B/C'ing these iems.
FX700: I can see why some regard it as the best dynamic universal. Timbre is great, detail is ridiculous, and it has this extremely lively, edgy sound that can be addictive on the right songs. The treble extends to the feet of Zeus, and the bass reaches down to the depth of the river Styx. Sorry, I love Greek mythology. I wouldn't consider the midrange recessed, it's just not that forward. It's there and it's detailed, but you can tell the bass and the treble are the stars of the show. There's a whole lot of bass, but it's so rich and textured that it's never really a problem. The overall sound is just so open, and the imaging is addictive. I feel like I'm listening to a headphone moreso than an iem, a really engaging headphone. The only (personal) con that I have with with it is that there is just so much treble on some songs. I feel like the overall sound is tilted towards the upper regions, with lots of bass to prevent the sound from becoming cold or overly clinical. When I listen to instruments like drums and cymbals, I can hear the treble boost in the overly lively snap of the snare, or the slight splashiness of the cymbals. I also feel like the treble tilt improves the apparent detail presented. Going back and forth with the GR07 on Mumford and Sons' "Little Lion Man," the FX700 presents about 5% more detail in the opening guitar sequence. Would I keep them for my daily use? No. They're a bit aggressive too aggressive, even at less than 1/2 of my iphone's volume and the mids are a bit dry for my taste. Otherwise, they're an EDM lover's dream come true, and the ultimate incarnation of the V-/U-shaped signature.
GR07: Way more polite than the FX700. I'd say the timbre is on par with the FX700, without that treble tilt, so it sounds more natural (to me at leas). Detailing is less aggressive, and the overall signature is more laidback, allowing me to listen for hours without a hint of fatigue. Dynamics on the GR07 are good, but not on the same level of the monster that is the FX700. So on about 10-15% of my library, I found myself longing for the edginess of the FX700. Keep in mind that the remaining 85-90% of my library was done better to my ears by the GR07. One of the things I love about this iem is that it lets me hear my music as it is. It's ever so slightly warm, without really coloring the music. That is not something I can say about the FX700. Not to say that the GR07 is boring; it's what I call a "lady in the street, but a freak in the bed." It's not a stripper with tattoos all over her body, but a girl with a little butterfly on her pelvis where you alone can see it. What my strange analogy implies is that the Gr07 is not an "always on" iem. It has no midbass hump, yet it can rumble your socks off it it needs to. It's still my favorite iem. The
IE8: The IE8 sounds way better than I expected, listening to the accounts of some. Yes, there is a midbass veil that obscures detail in the mids, but the rest of the spectrum is done pretty well. The highs are well extended, and have plenty of sparkle, and the mids, though veiled, are present and enjoyable. I didn't really find the soundstage to be that massive or distant. Listening to Amy Winehouse's "Valerie," her voice was intimate enough to keep the song together. Overall, the sound is pretty darn good, and I can imagine that the IE80 is even better. I have to comment on the beautiful, beautiful cable. It's so supple, and pliable. I think it may even be better than the GR07's. There's a member who keeps dumping on the IE8's jack because it's not gold-plated. To that, I say..."So?" This is one of the best built iems I've ever seen. Also, there is moore than enough bass on the IE8. It was enough to be slightly overpowering on some songs, and this was on the first knob out of 4/5!!
I can definitely see why all these iems are considered top tiers. I have to say that the FX700 is the classiest IEM I've seen in my life. It's simply gorgeous. It makes the GR07 look like the ugly duckling...
TLDR: FX700>=GR07>IE8
