So I seem to be one of the first people to receive one of these?
And I can't help but wonder if I got a demo unit - it came in some packaging that looked very tampered with and the space for a serial number is just blank...
Moving past that curiosity, I'm absolutely loving this thing. I don't know about "restored dynamic range" but in my eyes, it covers impedance matching, lowers the noise floor and more play on the volume pot means not being stuck in the <10% volume region with IEMs, where most of my less than stellar quality sources do an especially poor job (especially with low impedance loads).
I'm not going to pretend I have anything particularly high quality in terms of sources to compare performance with though - I have some distant memories of such things but it's been years since I've owned anything like that. I'm sure I could do better if I was willing to throw several times as much money at the problem, but short of that, I'm pretty happy with the purchase.
Oh and I'm using it with some KZ ZS5s at the moment - which seems to work fine to me (even with my on-board realtek, which is definitely not the case without the Ear Buddy), but admissibly I don't have any <0.5 ohm sources on hand to compare with.