Probably nothing to be honest. Phones have been trying to get into that slice of pie for ages, and most of the Chinese OEMs feel like cheap android rip offs, especially Meizu. But Sony, eh, never expected them to go down this road. But hey, on the other hand, I personally think that the Z3 is looking better then the iPhone 6, the lack of those seams is better imo:
And the glass back is definitely something I'm glad Sony has kept, its just so hard to go for a phone with only a glass front. I hope to god the Z3C gets the price low enough, cause while this will be too expensive, the Z3C at 300 would be perfect.