The US market is already very saturated and it's most likely the reason why Xiaomi doesn't bother entering the US market. Xiaomi is currently focusing on developing, high growth markets.
Anyway, I don't know how the Soundmagic E30 sounds, but the Pistons 2.0 sound better than the Soundmagic E10. The E10 and Pistons 2 have similar sound signature, but the Pistons 2 sound wider and have better clarity. Mids are also more pronounced on the Pistons 2. The E10 was good when it was released back then, but imo it's not worth importing now. If you are importing, I suggest you get a KZ ED Special Edition (or ED2, it's the same thing) instead. I just got mine, and they're like a better Pistons 2. Their sound is similar, but the EDSE's treble is a tad bit smoother and less sparkly, and the EDSE has a noticeably crisper low-end. Superior sub-bass and mid-bass detailing on the EDSE, and without the mid-bass bleeding you find on the Pistons 2. Soundstage is about the same, although admittedly I can't ascertain yet as my Pistons 2 already have nearly 100 hours of burn in while my EDSE has only about 3 hours on them from listening. I haven't started burning them in yet. I'd say the EDSE's sound is most similar overall to the JVC FXD80 and to a lesser extent the Yamaha EPH-100.
You most likely have the plastic edition of the Pistons.
P.S. Don't leave too much spacing between your sentences.