Firstly let's get some things squared away:
 
I do not believe in break-in. (Burn-in for those who don't understand terminology.)
I do not believe cable materials alter sound.
I do not believe amping makes a large difference.
 
Ah, the sub-$100 market. SO much competition. I've been a self-proclaimed audiophile since late 2010. I started out with Bose Triport, and SoundMAGIC PL11. Since then, I've explored the $20-200 market very thoroughly, mostly staying in the sub-$100 market. Of this, I have had the pleasure of owning:
 
Audio Technica M50 (purchased for 60. I firmly believe the T500, which retails at $80, is superior to M50 sonically.)
Audio Technica T300
Audio Technica T400
Audio Technica T500
Audio Technica ESW
Sennheiser HD280PRO
Superlux 668B
CAL!
Grado SR60i
Grado SR80i
 
I've also had the opportunity to demo, at-length, just about every other mainstream $100~ range headphone. (Mainstream by Head-Fi's standards; Shure, Ultrasone, Beyer, AKG, KRK, etc.) I've been doing extensive comparisons, and I believe that these might be the best all-round ~$100 cans currently available on the market. Can be purchased online for about $60-$70.
 
Sonically, let's observe:
 
Bass: Reaches down to 10hz. It extends very well in to the sub-bass. Plenty of rumble, but not a whole lot of punch unless it's called for. For lovers of Djent, you'll adore the texture of Animals As Leaders's, and Ever Forthright's kickdrum, as well as fans of more ballsy power metal such as Secret Sphere, Vision Divine, Vulvagun, etc. It does darkstep, and more commercial dubstep impressively well for an open-air can. BTW, don't let the apperance fool you, despite the back being opaque, it's a metal mesh, and to my ears, is very nearly as open as Grado cans.
 
Mids: This is where the Pioneers really shine. Presentation, and tonality are incredible. Guitars really sing, and grunt when called for. Bass guitar is ridiculously clear. Steve Harrison shines exceptionally. Mids are also laid on thick when necessary. Lovers of Sludge, Drone, Crust, etc: This is handled incredibly well. Fall of Efrafa, Downfall of Gaia, Celeste, and Converge sound excellent. Agalloch, Black Sabbath, and Insomnium as well sound amazing. It's weird how these cans do it all. When called for, they convey the darkness that these genres call for, yet due to the open-air, and massive 50mm drivers, as well as the gigantic driver baffle and velour pads, its extremely spaceous, and airy. Nothing gets muddied. VERY fast cans. Chaotic Hardcore, Noisecore, Grindcore, etc sound great.
 
Highs: Sparkly. There's not much to say. It's very reminiscent of Grado, but airier. I haven't heard ATH-AD500, ATH-AD700, or ATH-TAD400, so I can't compare. It never gets sibilant, unless the track is mixed to be sibilant. It can get a little hot with super bright tracks, but just drop the higher end slightly on the EQ, or lower the volume. These are in-door cans, so if they run hot, I personally recommend just to drop the volume rather than affect overall SQ with EQing.
 
Live Music: ...These are the best cans I've ever heard for live recordings, even up in to the $200 range. ATH-A900X, Dennon AH600, D2000, Sennheiser HD600, Ultrasone PRO580, Shure940, Grado SR125/225 can't touch these when it comes to Live presentation. (Sorry if I get any model numbers wrong. ) Their stereo positioning is impeccable. The stomp and cheer of the crowd, the sound of acoustic drums, live vocals, everything shines through. You can really feel, and percieve the sense of the large stage. Especially in open-air concerts, like Iron Maiden's "A Real Live One", or the sense of being in a concert hall, like with Joe Satriani's music hall performances, Yuki Kajiura's performances, live baroque recordings, or the sound of being at "The Assembly" with Machinae Supremacy.
 
Build:
 
Mostly metal, with a solid plastic double headband. It's self-adjusting, much like the ART Monitor series of ATH products. Huge, plush Velour pads. Behind the pads, is a massive piece of felt over the front, covering the driver and baffle to filter out HF. I haven't experimented with removing it, but I would assume it would make the HF white hot. The cable is thick, and protected by a thick woven cloth sheath. Strain relief is very solid, and positioned well. The jack is an extremely thick gold-plated 1/8th jack. The strain relief is kind of like a slinky. It's flexible metal. The TRS jack itself is gold, whilst the housing is solid aluminum. It's threaded, which works well for threaded 1/4th TRS adapters. For the DIY-minded purchasers: I recommend unsoldering the stock cable, and wiring a second gold-plated i-plug on the back for studio use. This cord is very well-made and worth salvaging for home/studio use. I also recommend cracking it open as it is single-entry, and sticking a 1/8th female pannel-mount within the cup, and buying V-Moda's audio-only cable. This will greatly improve its transportability.

Mild u-shape. Rather than going the XB500 route, it goes more for sub-bass extension, then mellows out in the higher bass/lower mids, roll offs where appropriate to keep the sound balanced, and smooth. Another roll off in the lower treble. Just a bit of sparkle.
 
Detail retrieval is inferior to some other 'phones in the price range. Superlux, and Grado have the Hesh beat in detail, and separation, and of course, headstage, open vs closed.
 
The Hesh perform much better with classical, acoustic, hardstyle/freeform/jumpstyle/hardjump/hard dance/etc. It isn't a problem with some genres of metal, but there was an obvious distortion, probably some sort of driver grattle, when playing early thrash, german power metal, and some european power metal.
 
personal issue: The cups are BARELY circumaural. They pinch my earlobes. Glasses-wearers, and people who love earrings, look elsewhere.
 
For 60-65, you can't go wrong with these. I'd argue these are probably the best basshead cans in this price bracket.

This is my first review in the past year of getting in to audio as a hobby. My roots started last year around April when I purchased the SoundMAGIC PL11. I heard my father's various Bose products, which introduced me to the world of high(er)-end audio equipment. Directly comparing The PL11 to the Bose Triport made me realize that my $16 PL11 were nearly as good as my father's $130 Triport, and it lead me to Head-Fi.
 
The SoundMAGIC ES18 use the same drivers used in the higher end E10. This is a budget-minded 'phone, sacrificing build quality to bring a higher quality sound to the lower income crowd, and they did a marvelous job of doing so. The 'phones aren't as machine-perfect as their higher-end models, but it's still far better than american bang/buck contenders such as Skullcandy, and other cheap low-end in ears saturating the consumer market. Mine shipped with some of the wire insulation stripped at the L plug, but not wire was exposed. No biggie.
 
The sound is identical to that of the E10. It's perfect for long-term listening. Gently emphasized Low-end, and Mids, slightly recessed highs. I notice a dip around 8khz, and it rolls off gently as it gets higher. Little sparkle, but absolutely no piercing, harshness, or sibilance.
 
Overall it sounds better than other Head-Fi favorites, such as the PL30/PL50, being newer, better technology, but it lacks the wow-factor that the PL30/50 have with their INCREDIBLE airyness and treble extension.
 
Comfort is above average, but don't take my word for it. My ears are weird. I owned a pair of Klipsch Image X10 that caused me unnatural amounts of pain, and I'm probably the only person on the planet that had that issue. Fit is just like any other straight-barrel in-ear around the same size as it.
 
A quick summary of the sound:
 
well-extended bass with great impact, and attack/decay, and well controlled. Full-bodied mids. Recessed highs around 8khz, and 16khz.
Soundstage is average.
Lacks the clarity, positioning, and treble extension of the older PL models, specifically PL30/PL50, but overall sounds technically superior due to using newer/better drivers.
 
Music used:
 
320kbps MP3s using Voodoo mod SGS. Genres include Progressive Metal, Power Metal, Freeform Hardcore, Hard Trance, DNB, Hard Trance, Classical (Baroque concertos, 19th, 20th, and 21st century Minimalist)