Yes to DHL shipping, and No to duties or fees. I'm quite smitten that it came this fast. I ordered a couple of dog collars two days before the 10SE that shipped from Texas, and that still hasn't arrived yet.
I got mine with the -7dB low gain, so I'm hoping this was a good decision considering most of my headphones are fairly sensitive (Grados, Ultrasones). I spoke to Kingwa about how hard it would be to switch it to stock 0dB low gain value and he said I'd just have to change out 4 resistors on the PCB, so it's comforting to know that it won't be too hard to change if I end up hating it (which I seriously doubt).
Something that I'm struggling with right now is how to go about converting my headphones to balanced. Most of my headphones are single-entry (K701, Pro 900, T50RP), so I'd probably have to drill into the second earcup and whatnot, which seems to be much more risky than I'm willing to get so we'll see.