Just got a pair of VSonic VSD5S today, and I'm quite impressed.
Packaging is great (like the premium ZS5 box), and includes nice accessories - multiple silicone tips, foam tips included, ear guides, and zippered carry case. Not that I care about retail packaging of a headphone, but it's generally a good sign when a manufacturer cares to go to the trouble of quality packaging and presentation.
They are comfortable to wear, and the insertion depth is just right. They sit flat enough that they could be used for sleeping. They come with silicone ear guides, but they're useless because they fall right off. Good news is the bare wires fit comfortably behind my ears without the guides at all. They can also be work down (when R & L sides are reversed), but bass is reduced as a result.
Cable feels nice - not sticky at all, not plasticy feeling, no 'kink memory', and it has very minimal microphonics (which is completely eliminated when the chin slider is used). I wish this cable was used on other IEMs. Not sure how well the cable will hold up to strains though, and the 3.5mm end could use some improvement (iffy looking strain, & the plug is comically too large).
The stock tips seem a little smaller than average when compared to almost every other brand - the stock M tips are more of a 'schmedium', and the stock L tips seem to be more of a 'marge'. Similar to the SM and ML sizes of the Spiral Dots.
The sound is warm and rich, with great soundstage (which is surprising because the shells are completely sealed w/no vents at all). Instrument separation is really good. Nice bright highs with shimmer and sparkle. There is a hint of sibilance, but I've found that's not all that uncommon with beryllium drivers. Sub-bass is a little weak, especially when straight worn down. With the next larger size tips installed though, the sub-bass fattens up nicely. Bass is tight and fast.
In general, the mids have just the right balance - instruments sound wonderful. However, there seems to be something funky w/the midrange that I can't quite put my finger on yet. I could be just imagining it, as I'm only hearing it with some tracks (specifically with some vocals). I only have a few hours of listening time so far - no BI yet, and not enough listening time to allow BBI. Maybe it will clear itself up with BI/BBI.
They scale well when amplified. A little thin sounding with the stock iPhone, better with the xduoo X3, and warm and lively like a fine wine when the FiiO E12 was added to the X3.
These are great for rock, metal, xpop (pop, Kpop, Jpop, etc), and EDM. Not sure about other genres because I don't listen to jazz, classical, etc.
All in all, I'm very happy with them, & I see these VSonic VSD5S becoming one of my favorite IEMs.
