I find products like this to be a little confusing from a consumer-value point of view.
I've had limited experience with the HTC One M8, but I will tell you it's a beautiful device. What I have trouble understanding is, that if you are an audiophile, like I am, why in the name of all that is holy are you listening to music on a phone? Why do you think that a multi-function device is able to deliver sound quality in the same vein or fashion as lossless music players? If you want to get serious about digital music, go FLAC, go lossless, at least go get a dedicate player like Cowon iAudio and listen to music more like it should be heard.
I like Harmon Kardon, I've been using their receivers for years, albeit I will say their quality and QA have decreased signficantly over the past years. Same could be said of other trusted audio brands like Klipsch, and the hardware quality of device manufactures like Cowon.
I'll get off my high-horse now, and say that if you are looking for a smartphone that plays music, you may just be looking for a little better sound than the drek that is out there now. So maybe this HK version of the M8 is right for you. I will say the AE-S ear buds look pretty, and nice and sturdy, surely better than typical ones you would get. Sounds like there are some equalizer options in there for customization as well. I don't hear anything else that points to improved hardware or audio codecs that may lead towards a better sounding experience beyond the headphones and software equalization though.
This video comes via pocketnow.