Finally, the long awaited HE400SE review. I have had mine since May, and always thought they were a fantastic buy at $149. I suspected that low distortion might be a factor in my liking them so much, and that does appear to be the case.
You have to ask yourself - why pay more? How much more enjoyment will a headphone $1000, $2000, or more likely bring?
My setup for them includes a $25 Rebel 4 TracFone using WiFi and Amazon music, and a three wire OTG always powered USB cable to a $109 Qudelix 5k. And the Qudelix great PEQ facility allows tweaking the fr as I like.
I did spend $42 for a balanced cable for the extra oomph. Definitely worth it.
So, for:
$25 TracFone
$149 HE400SE
$109 Qudelix 5k
$42 balanced cable
Or $300 some odd, I have IMO, a great armchair, desktop, and portable very enjoyable system. What's not to like?