my impressions between SM3v2 vs W4R posted on other relative SM3 threads:
it's a close call between the two. but if it's line out vs line out on my iPod 7g, then it's
SM3>W4 for me..
if both paired with the arrow 4g (damn ceph for this)
W4>>SM3
the w4 becomes a demi God almost seem invulnerable for me except for the Gods (Customs) 
I find myself yearning for the SM3s more when i listen to the w4 but coming from the SM3s to w4 just felt fine and nothing wrong.
W4 vs SM3
line out:
even with line out only for me, still the w4 bests the sm3 in almost everything (resolution) except for the imaging and soundstage
but I really prefer the SM3s for its more bass quantity and deeper, laid back highs sound more realistic to me, the imaging and lastly the huge surround soundstage which made my w4 sound obviously congested after being exposed to the SM3s.. the soundstage and imaging of the SM3s are unique, i felt that its soundstage could be very well utilized by the song. It's kinda overwhelming because it can also go toe-to-toe or very close with the ie80s gargantuan soundstage despite being a closed iem
MIDS are very liquid on the SM3s but for me this is where I find the W4 much better for my liking.. i already made an extensive side by side with the miss but i find the sm3's mids lacking a bit in clarity while on the w4 it sounds more fuller and real to my ears that I can hear the lips of the artist pouting on a song more convincingly than the SM3 (Domino by Jessie J @ bridge)
but i'm nitpicking too much here and if i'd wish that it also sound like on the w4s, then it's not earsonics signature anymore so it is very good on its own right.
HIGHS
i also favor the `sm3s having a very very good detail (on-par with w4) and quantity
it sounds more real on the sm3 than on the heavy highs of the w4
the soundstage is where the sm3s shine more than the w4
the SM3s make you listen to the music as a whole the details of the song is spaced out and utilizes the soundstage. it's also there on the w4 but it takes more effort from me to hear the micro details.
the details and micro details are just the same with the W4 but again with the sm3s huge soundstage i can hear the sound from its starting point, til it reaches its whole sound down to its very last decay. this obviously sounds congested on the w4
it's like a bubble wrapped up to your head where the mids are surrounded by the details
it's like you are standing there with the band and you hear ever the guitar and other instruments like they are beside you having an ample distance but this kind of imaging is quite polarizing on the hiphop/RnB/Rap genre, it takes away the intimacy the vocals sound distant. the um3x beats this easily on this genre
it is a stage monitor and the way I see it, everything is just there in the picture. the um3x is best on focusing on instruments and doesn't sound muffled no matter how crowded the song gets to.
the w4 gets your attention to its details while the SM3s presents it in a natural way and may take some effort to the listener to hear the details because of the smaller soundstage
where the w4 bests SM3:
like i said earlier the w4 bests the sm3s when it comes to resolution. i also find the w4 an upgrade over the sm3s when it comes to refinement
the bass is tuned for quality over quantity. it also reaches deep enough having more resolution especially on the mid bass department than the sm3. it has enough punch to satisfy me giving way for the mid bass to shine. there are songs that the SM3s struggle and sound muffled on the electric guitars but the w4 handles it easily showing that obvious very good resolution making it more easy to understand but also being more analytical than the SM3
MIDS
it sounds more natural in tone and fuller than the sm3. like what is said on the review on the head-fi, it has that natural distance between the listener so it sounds convincing, intimate, exact, real and never recessed for me on every song while on the sm3s, sometimes it lacks the intimacy because of the setting of the song and its front and center vocal presentation. it never sounds recessed either but the vocal quality sometimes really left me reaching for the w4s.
HIGHS
having more quantity and at the same time very detailed and packs a lot of weight and extension
Instrument Separation
both are very good but the w4 is just that better on separation because of the obviously more resolution on the entire spectrum. the sm3s don't lag either but when it comes to a crowded song, the electric guitars sound a bit off and hard to understand because of the more bass quantity. the imaging is very much different, the sm3s don't have that forward projection and is a surround soundstage showing very good space on the instruments. on the w4 all is placed in front of you but next to the sm3s it still has enough space on the instruments and sounds more refined (bright) a bit
the SM3s for me are really true to the song , sometimes when a song calls for more highs, it delivers and surprises me in a way that it could also have a lot in quantity like the w4. i really prefer the highs than the w4, when paired on my laptop, the highs are excellent for me. the w4 shows the highs very sweet and a bit louder but on the sm3s, it is indeed very sweet and i can almost picture on my mind the CYMBAL crashing up and down which i didn't find on the w4. Also the sm3s for me have more spark than the w4
W4 & SM3 featuring Headstage Arrow4G
the SM3s don't benefit much from it only giving a bit more impact and a bass like that of the dynamic drivers
the W4 becomes a demi God from it and becoming the exact sound and everything that i was asking for
imagine the excellent resolution on the mid bass department then the arrow 4g adding depth to it making it perfect sub bass punch and very rounded like the SM3s rounded bass. the rumble sounds perfect never deficient. the bass becomes very dynamic and is able to go toe-to-toe with the DDs and could even beat it easily. the ex1000's bass is the best bass i've heard but vs the w4, it makes the sub bass of the w4 weak but the resolution of the w4 makes the ex1000s mid bass a bit muffled
for me
the MIDS become a bit warmer and fuller and still intimate
the HIGHS are extraordinary on this one. even if i can picture the cymbals crashing on the sm3s the arrow gives a lot of boost on the w4s highs giving more spark and very realistic sound. the best of i can think of is the shutter speed of a high end camera,
when a cymbal is smashed, the W4 puts them in spades like how the camera captures every movement
the presentation even becomes very more impressive. what makes it more impressive is how the Arrow 4g makes the w4s soundstage larger not too wide and not too deep that I find the best and perfect soundstaging where every detail and instrument is presented very nice and doesn't sound congested anymore.
it puts you in a perfect position. like a Conductor in the middle of the orchestra, you see and hear every sound that starts and rises till it fades. there is no detail that passes by that you won't notice it.
final verdict:
I would prefer much the SM3s over W4 when listening to it line out only.. it is already very good without an amp whereas it also takes time to get accustomed to its unique imaging. after being exposed to it it makes my w4s sound underpowered and really need an amp like the arrow 4g to shine and get its full potential. the SM3s imho only need a good dac like on my laptop (neutral) to maximize the soundstage. the w4 also sound good on it but made the bass really lacking but also giving more resolution to it especially on the highs.
for now it's SM3>=W4
