Okay, so just got my Eightarc/Quanba Drone. Some quick impressions:
It's ridiculously light. Wow.
It's actually a *good* small size, not tiny like the Hori Mini or the Madcatz Alpha. Reminds me of the OG Madcatz Fighstick SE in that regard.
Slick looking. The slanted arm rest doubles as the USB storage as there is a small hollowed nook where the rest overhangs and where it meets the base. Overall, a good use of the real estate with a minimalist design. Oh, and slip grips on the bottom.
On to the important stuff: the stick feels awful. Flimsy, loose and mushy. Yuck. It's not even a better stick than the stock Hori's on the old DoA sticks for the 360, or the Dreamcast Green Goblin.
The buttons are at least serviceable. Nothing too terrible, but yeah, you'll want to replace them.
Now, I have yet to open it up, but to my disappointment, I just saw an Iplaywinner review that showed the stick is not 5-pin but wired in. So extra work for modding is needed. YMMV with that depending on experience. For me, I have never done that so it's a pain.
The buttons are normal QD's at least.