@wendyKL
My acquisition of the ATR, ZST, ZS3 and K3 Pro all came around the same time and I haven't put in as many hours with each as I would like. Depending on value, I think the ZST and ZS3 are the safest choices for the majority of people. Here's a quick rundown in order of best to worst for me in terms of value:
ZST
Pros - Beautiful build, looks cool, comfortable fit, replaceable cable, detailed sound, wide sound stage
Cons - QC issues(blocked vent), tip dependent(I get driver flex with silicon but none with foams), slightly bright and fatiguing
ZS3
Pros - Beautiful build, looks cool, incredible can't-hear-a-damn-thing isolation, replaceable cable, detailed, rich, warm sound
Cons - Uncomfortable vacuum effect when inserted, strange nozzle size, *irregular fit
K3 Pro
Pros - Easily the most technically accomplished and best sounding IEM of the bunch, great extension at both ends of the sonic spectrum, solid build, tiny ear pieces that are comfortable even when laying on one's side, tuning nozzles for bassy or balanced sound that actually work, nice, although large, carrying case that is useful beyond just storing the IEMs, MMCX connectors which allow for a wide variety of after-market upgrades
Cons - Eventually causes pain in my right ear, slightly bright, **QC issues plaguing recent purchasers
1More Triple Driver
Pros - Beautiful build, unrivaled unboxing experience, oh so comfortable, true universal remote, fun, warm sound
Cons - Cable is microphonic and over ear wear is awkward, sounds veiled and muddy next to K3, not worth $100 price tag but if you can find it for $60(Costco) it's a steal
ATR
Pros - Cheap!, comfortable, smooth, relaxed and inoffensive(non-fatiguing) sound
Cons - Sticky cable, smooth, relaxed and inoffensive(boring) sound
CKR9
Pros - Solid, durable build, warm sound with punchy bass
Cons - Awkward fit, crappy crappy microphonic cable, sound feels like it's missing something that I can't quite place a finger on, many better options for the current price these are going for
*
I complained to GearBest that the first ZS3 they sent me had a massive channel imbalance where the right earpiece was significantly quieter than the left earpiece and they promptly sent a replacement free of charge. The replacement unit also exhibited the same channel imbalance. Baffled I started tip rolling both units which is also a challenge because the ZS3's nozzle has an unusual diameter. Too wide for 3mm bores, but too slim for 5mm. KZ Starlines and MandarinEs Symbios were the only tips I had that fit. Still, with whichever tip, the channel imbalance remained. Then I had an idea. Pull out. Instead of the usual deep insertion I try to get with all my IEMs, the ZS3 only functions properly for me if I insert it all the way and then pull them out. 2-3mm will do it. At first I thought that the shallower fit might cause them to slide out overtime but the over ear cable and vacuum seal these provide keep them secure.
**
Luckily my issue with the K3 Pro, frequent disconnection with the two stock cables, was easily remedied by using a third-party cable. Others have had far more troubling issues such as nozzles breaking off, improperly aligned drivers, unofficial colorways and channel imbalances. For the time it takes to receive these from AliExpress and the headaches to follow in trying to get replacements and reimbursements I would say it's a much safer route to pick up the Audbos K3 from Amazon to get them quicker and easily replaced should there be an issue. Without all the problems cropping up on Head-Fi, as well my own issues, the K3 would have been at the top of my list.
