KZ - ZS10 Pro

Pros:
1) Practically the BEST hybrid KZ IEM so far
2) Lightweight yet robust, making it comfortable for long term/extended use
3 Descent in-box ear-tips) with medium-to-good quality cable
4) Metal grills

Cons:
1) Y spilt of the cable is plain dumb and tangle easily.
2) The rubbery material on Y Split swells over time
3) Slight hissing sound are audible on signals with certain type of music

-- Stats for Geeks--
- Audio Source: Redmi K20 Pro, Fiio BTR3, Acer Nitro 5, Lenovo Z2 Plus

- Sample: Pink Floyd, Led Zeppelin, The Beatles, Simon-Garfunkel, Bob Dylan, Pete Seeger (24bit@192KHz FLAC)

- Cable: Penon Audio Silver Plated SPC Cable, KZ ZS10 Pro Stock Cable, KZ ZS6 Stock Cable, KZ ZSN Stock Cable

I have had a Sennheiser HD599, Beyerdynamic DT770 Pro 80 ohm, iFi Zen Dac, Fiio Q1 Mk II and KZ ZS10 Pro was my first IEM. Out of the box, 1 notable thing is that the Extra Earbuds given is very cheap in quality and none of the earbuds were comfortable for me out of the box. (Even though over time, the silicone gave in and now feels more comfortable). Another notable thing is when you plug it in the audio sources, the noise floor was obviously heard, more so with laptops and less so with Zen Dac, even less so with Fiio Q1 (best). The noise floor is not much of a problem when the music is actually playing and with moderate volume. Then cable is not the most quality cable as well, but its ok, braiding is good, doesnt feel like it is going to wear off soon, not like rubber wires.
Also to note, KZ in their manual itself, suggests that we do a 5 minute burn in to improve the sound quality, and it looks like it was the case. Initially, I was disappointed by the sound but it turned out well after some time. Also, with silicone earbuds, it feels like these IEMs traps air and creates pressure. I think foam earbuds will not have this problem.
Now that all the quirks are mentioned, let's talk about sound quality. In short - 2 words - Details, Tight Bass.
Sound signature is very satisfactory. Vocal is intimate, which I like it that way. Soundstage, (since this is my first IEM), I did not expect it to have this much. It was like I was wearing an "audio helmet". In some cases, some high end "reverb" music had an even larger sound stage, literally felt like coming from the room itself, rather than from IEMs. Details are amazing too, they were in par with the On ear headphones I mentioned above, if not better. In one of the songs, I could hear the sound of water droplets in the background that felt like it was coming from the room. The bass response is just oh my god, it was so tight and non-mixing with the mid range. It was similar to be having a separated sub-woofer inside the IEM and it is literally true, because the Dynamic driver inside the IEM is just meant to produce bass and 4 BA drivers - 2 for Mid range and 2 for treble. Beware, if you have experiences with neutral sounding / audiophile headphones, then you would understand and like this, or else if you are a basshead, then you would probably will feel the bass is lacking. If you're willing to enter the audiophile world, then this sound signature is definitely what you would want to train your ears with.

Last note, all the sound explanations I've given is with iFi Zen dac and Fiio Q1 dac/amps with Tidal Hi-fi audio and especially with music that are mastered well. If you're willing to use it just with the Laptop's / Mobile's audio jack, you could scale down my experiance to a certain amount. Rest assured, this will definitely sound better than a typical 1000-2000 bucks earbuds and definitely even more so than bluetooth earbuds in the 5000Rs. range. If you're willing to buy a dac/amp, I like the Q1's sound signature better than the Zen Dac's with this IEM, because Q1 has less noise floor, vocally intimate and warm sounding, on the other hand, ifi has a better sound stage, more details (with firmware 5.3c) and more realistic vocals.

As of 2020, You might also want to check the ZSX Pro, people claim that it is better and more refined than ZS10 Pro. I did not know about it before buying ZS10 Pro, but anyways, I'm happy with this as well overall.

The review compares the zs10pro with the SM e11 and the e50. I bought the e50 for 2.4k @hzone. When my e50 gone untraceable I ended up buying e11c as I considered it as an alternative. The sound signature is very narrow V-shaped as the mids sounded dull compared to the e50 which had the balanced kind of w-shaped sound. The e11 isn't bad but it needs to be driven at least 90% volume in order to balance the mids with other frequency. Listening to the high vols at all the time is impossible because each audio is tuned differently. I felt I need to buy one more earphone and decided to buy a bluetooth pair. Later I decided to try the IEMs which can be convertible to wired and bluetooth by differing the wires. The zs10pro comes as my choice after filtering my budget. First impressions are these are bulky and heavy on the ears which take time to get used to. Like earphones, I don't think this can be easily slipped on to the pocket while traveling. One may need a bag or something. The cable thickness is good but the plastics used for microphone and around the jack are poorest. The sound shape is balanced and neat up to 90% vol. Above which it may sound harsh and I never tried as it gets louder. The nightmare part of these IEMs was the pin connections. U need an eagle eye to see L and R markings and match the pins correctly. You need to be cautious while giving the connection as it's not as easy as plugging your phones every day for charging. It's best to leave unplugged those pins frequently. The blue tooth module isn't available with the Indian retailers and I hope they 'll be stocked soon. It's a decent purchase overall, The audio quality felt better in all the frequencies. I recommend this product if you want IEMs. But if you want a lightweight gadget look for some other.
Earpiece Design 3/5
Cable length and quality 2.75/5
plastics (jack/mic) 2/5
Comfort 3/5
Sound 4.25/5
Vfm 3.25/5

ahhhh let's see or hear or read
I saw I heard I'll write and you are reading :
so lest start with build quality then:
Plastic body with polished stainless steel backplate feels nice and solid, has just a bit weight to it that gives you the feel of really good build quality. The cable is not so bad either pure Cu with a clear coating on it, rubberised Y split box and 90° 3.5mm TRRS connector for a microphone so you can use ZS10 "PRO" to call your (whomever you want to talk to). The silicone tips: just throw them away and buy nice memory foam tips (you'll notice an instant boost in the low end with memory foam tips).
Now the hard part The Sound:
Sound is a very subjective subject. This has amazing low-frequency rumble
clear mids and crispy highs that will give you the information that you might never heard before plus you'll hear is spectacular imaging slightly narrower soundstage then T2 excellent sub/bass. I was listening to "Bad Blood - Vintage Ella Fitzgerald Jazz Taylor Swift Cover ft. Aubrey Logan - PostmodernJukebox" I clearly heard there was a clip while Aubrey Logan singing those high notes. I mean this IEM gives you those kinds of details so clearly that you'll notice immediately.
the low end is also nice tight and the sub will rumble your eardrums like an earthquake's frequency hits the 7 story building.
In just a few words: Just buy these IEMs, these could be 2nd or 1st best IEM under 4000 hands down after or before TIN T2. If you have T2 also give it a shot.

Cable is not good quality...other than that good

KZ - ZS10 Pro

This is my first Chi-fi IEMs. And i have no regret buying it.
The low end part if frequency rage is very precise and boomy. The bass part is really good and its doesn't effect other frequency. Mid part or vocals are also crisp. And high frequency rage is sharp and bright. Sometimes the brighteness of these hight frequently may sound unpleasant at high volumes. But its just me, i like average treble.
Overall these earphones are really good.
I own a pair of Shure SE 215 IEMs also. So ZS
10pro are not at that level.
If SE215 is 6 out of 10 ZS 10pro must be at 4 out of 10. And ZS are like half of SE215 price
Hope this review helps someone.
And thanks to headphoneZone guys for such fast delivery even during this pandemic.

KZ - ZS10 Pro

Gives a precise sound quality but not good bass.