I've had my CKR90 since Wed. afternoon. I bought the "bulk version" so, with the $15 code, they were $94.
First off, the tips that come with them are not the CKM55 but are indeed the ones that came with the CP200 and CLR100 Sport2 etc. so they are better. The sites all say replacement tip model CKM55 which are black but these are translucent gray and have better bass than the old CKM55 tips do. They do sound good with the CKR90.
They are big earphones...
...but they fit quite well. Better than the older CKR, the E40, or even the CKS1100 which seem to share the same front cap.
I do think they are handsome. Elegant is the word that pops into my head. The dark pewter brown-like color the machined rings, and the fine rised "AUDIO-TECHNICA" on the outer edge of the housing make them understated but very upscale in looks.
Upon using them and learning about them for the last couple of days I can see the different reports of the sound signature. Some reports of thicker sound and some reports of sharper, cleaner sound. Either thicker than the previous CKR9 or not. I have heard both based on the fit and seal. I think it comes down to the seal. They need a good tight seal or they sound on the thick side. Once you get a really good seal they get noticeably tighter, sharper, and transparent sounding. While the fit is better for me than the ones I mentioned they are still BIG and won't won't work great with all tips. I feel the JVC tips don't give a great performance here while on the CKR9 worked well being more open and not needing as much of a seal. The size combined with the short length of the JVC tips or other sort length tips makes them sound lower Res and thicker and just less resolving.
Over all I think the sound is an evolution of the CKR9. The unmatched driver size is trying to put forth a little more of a sub woofer effect on them. Works well if you have the right fit and are not underpowered. Though they are easy to drive and anything not lacking will drive them fine other than getting a bit more tightness in the lowest bass and the most size stage they can have.
You can get nearly the same CKR9 bass amount with a leaner source or the right EQ. I find the CKR90 works/agrees nicely with the Cowon BBE presets.
Other than the same "Sound Reality" as the older CKR, the 90 brings a bit more 3D to the sound over the CKR9. Things can be placed front to back on top of each other but the stage is not as tall. it is more even and round. The CKR9 was taller than wide and one may like that better or like the CKR90 even height and width with the more realistic front to back placement. Same natural sound with great resolution is there. Great detail and very sensitive pick things out easily and lets you hear them. texture is all there to. Ety have nothing on these as far as resolution yet the emotion is still there and the dual drivers can place things in front or behind each other in a way few single drivers, armature or dynamic, can.
The bass seems about equal in quality w/o the open back vent. I do not have anything other than my notes from when I had the CKR9. I'm thinking the bass does reach a bit lower but can't totally confirm that. I do hear that the emotion is conveyed a bit more across the range and they mids and treble, my issues with the CKR9, are improved nicely. Treble is more realistic, pure of tone, and free of grain. The mids/vocals are up more and more emotive and not as dry or slightly dull anymore. If you have heard the CKR9 you may have heard the bass as wonderful but the rest of the way up was just not as high a quality. I hear the CKR90 as a maturation with the more even stage and vocals and highs that are now on par with that sweet bass.
Some things are easy to hear and recognize. Some I would need a CKR9 on hand to really see. Is the bass really a little lower? and the now 42,000Hz treble go a little higher?? Those are not a noticeable to say with any certainty so I stuck with the big things.
Wasn't that thrilled in the first few hour till I learned them a bit more. Thinking I was glad I only paid $94 early on

I am not sure these are an audition at the shop and really "get them" kind of earphone. At least it may be harder for some. Now they are more than just liking them and they are now clearly my current "flagship".