I'm seeing a lot of requests o n here for reviews of this CKR100IS. I don't own these but I do own AT's CKS1100iS. They have 12.5mm push-pull drivers almost similar to the purported 13mm drivers here. The basic specs of my CKS1100iS are almost identical to these: 5-40kHz, 200mW input, 50ohms impedance, 108dB sensitivity, same A2DC connectors.
The majority of my audio equipment is IEM's including Empire Hermes VI, Noble Sage Silvers, Vibro Earphone, Campfire Lyra II. I think I have some good IEM's to compare to these CKR100IS's.
I can tell you of all my IEM's, the AT's are my bass monsters. Right out of the box with no EQ modifications, these are severely bottom heavy. That may work for the most avid bassheads, but for me I have to juice up the high frequencies with whatever EQ I have on my various sources. Once I do lift the high end up though, these are stupid clear and can be really, really fun to listen to. However, the bass is just so damn big that I find I can only last an hour or two of listening to the CKS1100iS before I have to take a break or switch to another IEM.
From a manufacturing perspective, my CKS's feel really well made with nice materials, if that's important to you. I hope this helps gives a little insight.