Although I felt the HE-400 was nothing short of spectacular considering its price point, I came to experience that the HE-500 did, to my ears, produce a better overall sound, especially the midrange. The HE-500 ($700) however is twice the price of the HE-400 ($350 preorder price) and so did it sound 200% better than the HE-400? no lol. Nevertheless, the sound difference was substantial enough for me to strongly prefer it over the 400. I listen to mainly classical, jazz, and alternative artists and the 500 delivered all of them perfectly with the right amount of oomph whether it was the bass lines, vocalists, or cymbals, etc. While I appreciated the extra gravitas of bass on the 400, I felt that its sound signature would be more beneficial for electronic/hiphop/r&b type stuff which I don't particularly listen to very often. Not to say if I played classical/jazz stuff on the 400 that I would feel underwhelmed; on the contrary, tracks I played by Julie London, Sinatra, and Tchaikovsky came through with intense emotion and force, however when I then quickly switched to the 500, it was immediately evident that the 500 had a much more umm...creamier...silky liquid smooth midrange with just the perfect amount of bass and treble (for my taste). Like Julie London's Black Coffee sounded so lively, effortless, and seductively sensual that I often felt a tingly sensation at the beginning of each verse. On the 400, didn't get that tingle but was still very much satisfied. Overall, I vehemently believe it would be much more fair to compare the HE-400 to the 500's sound rather than the HE-300. But for people ordering the HE-400 thinking they'll be getting the HE-500 for half the price, will likely be quite disappointed. Ultimately, you get what you pay for. So yes, in a sense, the quality difference isn't "very big" but at the same time, it kinda is lol. For me, that midrange coupled with the goldilocks balance between upper and lower ranges was just too addicting, not to mention I loved the gun metal grey vs dark blue. But $350 for headphones of that quality was just too good to pass up for me. However, even having preordered the 400 I still very much plan on getting the 500 as well, eventually anyway. And to reiterate, I really wish I could compare them side by side in a much quieter setting as I felt the large amount of ambient noise of the convention really distracted from what would otherwise have been an epic listening experience.
Now one thing that bothers me besides not knowing if they are worth the money soundwise is the weight.
