Initial early impressions.
I am still getting to know the Hero (the LX SE has been a bit distracting the last couple of days!), and while I agree with some of
@Resolve's comments about the Hero and Nio directionally, I don't agree fully (of course, this is the beauty of this hobby, isn't it?).
First, I really enjoy his reviews and think he does a great job of balancing technicalities with an easy-going attitude. Really think his reviews are excellent.
FWIW, I believe he used the m15 module with the Nio, and I used the m20.
I found the Nio (w/m20) to have more bass than the Hero (i.e., more quantity), but I also found the Nio's bass to be of much lower quality - splashy and lots of mid bleed. To my ear, the m15 module was far too bass light, if that helps you calibrate my preferences versus Andrew's!
I do agree the treble on the Hero is a bit bright, but I just popped on some foam tips and have since found the treble quite nice - still on the bright side, but I'd use the word "crisp" (which I believe has a positive connotation) than "bright" (which leans negative).
I find the Hero to be "balanced with a treble tilt," if that makes any sense, with a very nice stage (not as wide/holographic as the Solaris 2020, but puts up a fight for sure).
I would not characterize the Hero as a V-shaped signature, personally, and certainly not anywhere near the signature of the Valk, for example, which I do think is a strong V (and the Hero's treble is
much tamer than the Valk's treble).
Also, to be transparent, I'm selling my Nio - couldn't justify it with the rest of my collection, and struggled with the bass quant/qual trade-off. The Hero fits my preferences and collection much better than the Nio.