This IEM is for those who love the sound of natural instruments and the human voice. I purchased these from Massdrop as the Universal Pro-To-Go version. These are the 2nd Gen of the UE 18+ Pros (discontinued).

Tonality and Resolution: 5/5
No other IEM I've listened to comes close to the mids reproduction of the 18+ Pros. Textures of male and female voices come across vividly, and instruments sound exactly as they should be. The True Tone drivers really make a difference in reproducing the signature harmonics of each instrument, so much so that I find it hard going back to other IEMs which sound sterile and artificial by comparison. Also, because of the smooth treble, I can listen to this IEM the longest - no fatigue whatsoever.

Separation: 4/5
Great imaging, and ability to hear all parts of an ensemble. That being said, the IEM is extremely coherent. Feels like sitting in the middle of an orchestra.

Detail: 3.5/5
You get micro-detail with this IEM, but not with the clarity of a more neutral-sounding IEM. This is NOT an IEM for analytical listening (unlike the InEar ProPhile-8), however - you'll forget you even wanted a higher level of detail listening to this IEM.

Soundstage: 3.5/5
This is in relation to the Campfire Andromeda. Not huge, more on the intimate side, but can range depending on the recording.

Driveability: 3/5
My standard source is the Pico Power and Dragonfly Red out of my Macbook Pro. These IEMs need to be amped to reach their full potential.

Bass: 3/5
Good texture, although there's a bit of sub-bass rolloff.

Mids: 5/5
The best of the best.

Treble: 4/5
I don't like sharp treble. While this doesn't sparkle like the Andromeda, it has enough definition to bring out the right timbre while never fatiguing my ears.

Conclusion:
The most natural sounding IEM I've ever heard. Jazz and classical lovers - this is it.

My first entry into the world of high-end portable audio was the AKG K3003. The detail and resolution blew away every other IEM I had listened to in the past. It was enough for about five years and then I got sucked into Gear Acquisition Syndrome, and the constant money-sucking desire for incremental returns.

That journey took me first to the LZ-A4, Noble X, FutureSonics G10, Campfire Audio Andromedas, Aurisonics ASG-2.5, InEar ProPhile-8s, Sony XBA-N3, JVC HA-FW01, UE 18+ Pros (2nd Gen), IMR R1, Oriolus MK2, and finally the Hyla CE-5.

Yes, I have a lot of TOTL IEMs. However, almost all of them are all-BA designs. I longed for a return to the detailed and clear sound and natural decay of my OG hybrid, the AKG K3003. For all its clarity and micro detail, what had driven me away from my AKG K3003 was the light bass (I'm a basshead) and piercing treble. Today, I can say that I've found my endgame in the Hyla CE-5.

Tonality: 3.5/5
With the right low-impedance source, it is the perfect W-shaped signature that gives layers of high quality bass, smooth and engaging mids, and non-piercing but extended treble.
Straight out of my MacBook Pro headphone jack, there was audible hiss, the bass was way too strong, and worst yet - the mids sounded lifeless.
My preference is for the Dragonfly Red out of my MacBook Pro - what a world of difference this made. The mids (both male and female vocals, instruments) sounded so much fuller without losing that clarity and separation. Using the iPhone dongle, it sounded close enough to the Dragonfly Red, but with less dynamic range.

I'm a bit surprised at what a difference the source made in the sound of the Hyla CE-5. In that way, it's a bit like the CFA Andromeda.

Separation / Imaging: 4/5
With a low-impedance source and black background, the CE-5 does admirably and allows you to hear layers of detail through the entire dynamic range. Listening to classical pieces, I can hear every instrument section in their "space" in the orchestra. However, the amount of resolution and detail cannot match my InEar Prophile-8. Those are in a whole different class.

Soundstage: 3.5/5
The soundstage is wide, but not nearly as wide as the CFA Andromeda. With the Andromeda, I would occasionally turn my head to look at the direction of the sound and then realize it was from my music. With the CE-5s, I never get faked out.

Driveability: 1/5
I would not recommend any high-impedance sources (unless you're a fan of massive amounts of bass, and thin/lifeless mids. Smartphones and similar devices allow the Hyla CE-5 to truly shine (IMO).

Comparisons (vs. other TOTL I own or have owned)
vs. CFA Andromeda:
A pretty neutral IEM, with a touch of warmth and AMAZING soundstage. Best soundstage of any IEM I've heard. However, it didn't have the coloration and richness of mids I was looking for in an IEM. Nor did it have the quantity of bass. I want rumble. CE-5 provided both of those.

vs. InEar ProPhile-8:
Extremely neutral IEM, with probably the best bass quantity out of all my TOTL BA IEMs. Soundstage is smaller than Andromeda, probably a 4/5 on my rating (occasionally get the feeling of sound outside your head). Despite the incredible amount of separation, imaging, detail and resolution, the overall sound is very sterile. And I much prefer DD bass decay.

vs. Oriolus MK2:
I thought the MK2 would be my endgame hybrid, until the CE-5 came along. Now, I find the Oriolus too warm with not enough detail for my liking. The bass quantity is also too much for me on the Oriolus. The mids on the Oriolus are gloriously rich, however.

vs. UE 18+ Pro 2nd Gen:
Best mids out of the bunch. However, the tonality is VERY warm. It sounds like someone wrapped the sound in leather and you're listening to it in a room full of mahogany furniture and dusty books. Some say the timbre is very realistic. Soundstage is not as impressive as the PP8 or Andromeda. Has a very intimate sound. Resolution, imaging, and separation are almost as good as the PP8 on this. Bass quantity isn't as great as the CE-5.

I've left out comparisons with rest of the IEMs I own / have owned as the others cannot compare to the CE-5.

Conclusion:
If you're a fan of W-shaped signatures and love DD bass decay, this is the TOTL Hybrid IEM for you. The bass quality is unmatched by any other IEM I've heard - in a lot of BA IEMs, great separation in the mids but I've never heard the same phenomenon for bass. This is truly unique. There's so much separation between the sub-bass, mid-bass, upper-bass that you can hear the difference between bass drum kicks and bass lines. Unreal.

At the same time, the bass quantity isn't overwhelming, but has great growl and rumble. Bass slides give me goosebumps on the CE-5.

Vocals are a bit ahead of instruments, but everything sounds clear and well separated with a hint of warmth. Very coherent.

In terms of treble - I'm not a huge treble head, but I feel there's decent air and sparkle comparable to the PP8.

Based on my own preferences, this is my current favourite IEM and daily driver.