64 Audio Fourté Blanc IEM Review. Limited Edition: Only 500 Units Made 

Hey sorry for the delayed response! I really love both (I'm not just saying that, both of these made it onto our top 10 list this year which we just published). Since it seems like you're most interested in low end, ill focus on that: the OH5 has a widely boosted low end - subs, mid bass, and low mids are all brought up. It's a thick, meaty quality that can be heard across multiple components to a song. The hook X, on the other hand, has more narrow and more dramatic boost focused on bringing up subs and mid bass: this gives that emphatic boomy quality that's specifically tailored to bringing the most about of kick drums and bass lines. Another way to put this, the OH5's prominent low end is supplying a broad, full texture, while the Hook-X is about moments of low end impact. The OH5 is a better IEM ultimately for its imaging, and in my opinion, its midrange. That being said, I think the Hook-X is a ludicrously good bargain considering its price. The bone conductor in the Hook-X has a subtle presence - it's there, but you might have to look out for it to really notice it (unfortunately, the only IEM with truly prominent bone conduction that I've gotten to try is the Legend Evo. There are others I haven't tried though).

Definitely true that IEMs require more upkeep and pose more health risks - counterpoint: someone who doesn't own IEM's may never experience the ethereal joy of feeling a kick drum slam against the inside of their skull. Things to consider... ; ]

@@MajorHiFi Very True lol!! :)

owning iems are NOWHERE near as troublesome as you claim. i own 20 of them and have broken only 3 of them and they were all due to my fault (stepped on 1, sat on 1, and completely soaked 1). using iems is so much easier than headphones for me