I've had my DX80 for a couple of weeks now so I will share my experiences since this thread helped me so much.
I purchased my device from B&H. The first arrived without the shrink wrap, a dented corner and missing accessories. The replacement had all the parts but was also missing the shrink wrap. I was visiting the USA so I didn't have time to deal with it anymore.
Fit and finish. I spent over four years of my life in China working in electronics manufacturing and I am now on the hardware side for a Telcom so I would say I am likely more detailed oriented than normal. Compared to other consumer electronics, I would only give this iBasso DX80 fit and finish a 7/10. There are too many places where tolerances are very far off.
Sound quality
I am replacing a smartphone so my only goal so far was to get a line out that was more use able for my Valhalla2 and new headphones.