Got it today ($40 silver plated cable from lunashops for IM03/IM50)!!! Just took a bunch of pictures and will post a review in the next day or two in IM0x thread
As an early impression: amazing build quality, snappy connectors with a perfect fit, soft cable shield (no springy effect), cable feels strong, goes over you ears without a need for ear hook guides and stays around your ear thanks to a chin slider, hardly any microphonics effect. Sound quality - DEFINITE improvement! But I would consider it more appropriate for IM03 rather than IM50. With IM03 (using UE900 tips) the sound gets brighter, like a veil lifted off (and IM03 with a stock cable is great to begin with), you hear more definition and details in sound across the entire frequency range. The change is not just subtle, but actually noticeable. But improvement with IM50 (using hybrid tips) wasn't as tolerable for my taste because of a very simple reason - overwhelming bass. IM50 has enhanced bass to begin with, but now it's borderline basshead quantity. You get the same enhanced details but sub-bass became a little too much for me which took away focus from upper mids. Still well controlled bass without spilling over, but just a bit too overpowering.
Will do more listening and some burn in (from my experience, cable goes through some burn in settling as well), and then will post my final thoughts about it.