Contributing, based on my impressions :
Sennheiser IE8
Pros: Unmatched soundstage for an IEM, adjustable bass port, smooth mids and highs, very musical, replaceable cable
Cons: May be a little laid back, has a mid bass hump that tends to muddy the mids, can be alleviated by shallower insertion at the cost of isolation
Works well with: Just about any genre, but excels well on electronica, hiphop/RnB, rock, classical
Westone 3
Pros: Great EQ response, slightly above average soundstage, good bass and highs, a bit on the warm side, lots of included tips
Cons: Midbass hump, has some sibilance issues, mids are somewhat recessed and has tendency to be tip dependent
Works well with: Pop, Rock, Metal, Jazz
Westone UM3X
Pros: Very good EQ response, incredible instrument separation, imaging and detail, excellent mids, scales well with good a source and when amped,
Cons: has a tendency to sound flat/neutral on some recordings, bass lacks impact, mids may be a bit too forward, small soundstage, very few included accessories
Works well with: acoustic, male/female vocals, jazz (may work well on other genres, depending on source and recording quality)
Shure SE530
Pros: Excellent Mids, good soundstage, instrument separation and detail
Cons: rolled off highs, detail lacks body, MAHAL.
Works well with: male/female vocals, jazz, acoustic
Ultimate Ears TripleFi 10
Pros: very good detail, crisp highs and excellent bass presence, very good soundstage
Cons: recessed mids, fit could be a pain in the neck, stock cables harden over time.
Works well with: pop, rock, electronica, metal
my top tier rating:
1. UM3X/IE8
2. W3
3. SE530
4. UE TripleFi 10 (would actually fare higher if not for the poor fit issues with my ear)
still wanting to hear:
1. Ortofon E-Q7
2. Grado GR8
3. X-Jays (once released)
4. Monster Turbines Pro Copper
5. Apuresound recabled ER4P (basically an ER4P on BANKAI)
6. Earsonics SM3