So these arrived today. Have only spent an hour with them but have some thoughts already. I'm mainly going to give my opinion on the bass response and vibration haptics. Have compared to GK Kunten (both use zenith driver) and Penon Archangel (unfair premium bone conduction comparison).
Test track I was using was 'Georgio by Moroder - Daft punk'. The last minute of the track, has a very deep but tight sub bass kick drum with elements of electronic and rock (guitar, bass, synth etc) and gets quite busy, in a good way.
As expected the Vibe X has a similar sound signature and quality to the Kunten until you hit the low end. There's noticeably less sub bass than the Kuntens and a buttload less than the Archangels. This translates to the kick drum being less 'present' in the mix. Then on a tom hit, the vibes suddenly do their thing and you feel the hit of the toms in your ear canal thanks to the BC/vibration driver. Bass guitar can sound a bit bloated at times. Sounds like the BCs are most reactive to around 80-100hz - kind of like having a subwoofer without room tuning applied where it reverberates more around certain wavelengths.
They shake and thump quite noticeably when touching them with my fingers but in the ear the effect is significantly less noticeable at least for my ears. I tried different insertion depths and angle etc and could definitely feel the vibration but not as much as I was expecting and a more narrower frequency response range than I was hoping. Interested to hear other people's opinions though as I feel the vibration drivers might react differently to various individuals ear anatomy. Technically they are meant to vibrate down to 5hz or something silly, maybe my ears just feel/detect it more at 90ish hz.
If they do a V2 down the track, I'd love to keep the Zenith driver, Kunten tuning and add a modest bass boost and have the vibration driver respond across a broader range with the most noticeable point around 40-60hz. Just like with large speaker systems/live music where you begin to 'feel' rather than 'hear' the lower frequencies. Basically copy how Skullcandy implement their crusher haptics, refine it and apply it to a high fidelity iem.
TLDR: mid and treble similar to Kunten, suprisingly subdued sub bass (60hz and below), vibration not very consistent across bass frequencies - responds most to 80-100hz. Suffers from some bass/midbass bloat.
If anyone else has received theirs I'm keen to hear your opinion!