I'll start off saying that if you want to make friends, better not be 100% honest 100% of the time. But since I didn't join head-fi to make friends or improve my social life, I can afford to be...myself.
"Get on with it, what's the screwing verdict?"
The UM3X is the best universal IEM I've ever heard and they give my ES3X a run for their money, pure and simple. So, if you're one of those who disliked or hated the UM3X sound, my advice is to never consider the $850 ES3X, as you'd 'only' be getting a slightly improved version of the UM3X.
OK now, let's get to the boring part of this most long awaited post (and nearly as much as last year's excitement over HeadphoneAddict's 3-way shootout between the ES3X, JH13 & UE11.)
Improvements:
Westone certainly listened to their customers with the new UM3X, and unlike Shure, they made some changes only a year after the original UM3X. Shure, by contrast, took much longer to change their SE530 (3 years, I think).
The # 1 improvement has to be the addition of removable cables, which unlike Ultimate Ears who used a lower quality cable for their Triple.fi 10 & Super.fi 5 to that found on their customs, Westome uses the same 50" braided black cable used in their ES (custom) series.
The Y split, unlike last year's cable which was too close to the chin (just like the SM3s), is just like the customs cables with a very decent distance from the earpieces to the Y split. The difference being about 2" (5cm) longer between the old UM3X (and SM3). Also the ES series cable is more tightly wound than the older UM3X & W3, identical to the SM3.
Now Westone include the same tips that were included with the W3, ie now you get 10 different eartips. Last year's model only came with Comply tips.
The new Westone case is better than last year's UM3X's and the original W3's case (don't know if it's changed), not only in its shape, but also in the workmanship. Last year's case felt quite cheap by comparison and the W3 was far too soft for such an expensive IEM.
The new UM3X packaging is much smaller and much better designed than last year's very tacky looking packaging. Also, it's more environmentally friendly as it's not 100% plastic like before.
Comfort-wise, the SE535 & UM3X are very, very close, but the swivel mechanism on the 535s just makes the whole inserting process too long and awkward and a little frustrating at times. The indestructible 535 cable remains a bit too stiff for my taste but very nice to look at, and it causes some microphonics, but not a lot. Also, the memory wire on the new UM3X isn't quite as long and bulky as the SE535's - this is a good thing. Both UM3X & SE535 are a little more comfortable than the SM3
The SM3 cable is exactly the same quality as the UM3X, except for the Y split distance to the shells and the obvious removable feature. Apart from that, the rest is identical. I'm sure EarSonics get their cables from Westone or from the same manufacturer.
On the box the SE535s state: "Made in China". The SM3s: "Designed and Made in France". The UM3Xs only: "Assembled in the USA"
The sound:
Seems my memory isn't as bad as I thought. Well, not really. I always remembered quite well how close my UM3X's sounded to my customs, hence the good memory. But I can now confirm that all the comments I've made re SQ comparing the UM3X with the SE535s & SM3s still stand.
The UM3X sounds closer to the SM3, but the SM3 is the UM3X but with a veil (or blanket) over it. The whole sound presentation sounds muffled.
Compared with the SE535s, the UM3X bass has authority, quantity, quality, and impact. The bass on the 535s is too polite. I still find the treble on the 535s a bit too pronounced and 'thinnish' (for lack of a better term). The UM3X treble is not recessed at all, it's just about right, pretty much in between the 535's & SM3s. Mids on all three are excellent, but the SM3 has that veil on all 3 frequencies. The mids are great on the 535s but feel kind of 'naked' or stranded as the bass and treble don't do the 535's mids justice.
Great to confirm again the excellent instrument separation coming from the UM3X, which remains one of it's greatest assets, VERY close to my ES3X - simply incredible!
I don't hear that closed/ boxed-in sound that a handful of people have described.
On the whole the UM3X sound fuller, more convincing, balanced along the whole freq spectrum, neutral and they ARE a joy to listen to. Now I don't feel I'm missing out.