I got me one of these too, ordered from a Dutch guy who'd better pay back the import taxes caused by him drop-shipping it while pretending he had it in stock, or he'll be getting some negative publicity. Having to wait 3 weeks was bad enough.
I already had a ZGPAX S5 which I damaged, which is why I got this as a replacement. This is exactly the same hardware, as evidenced by the ability to restore a complete TWRP backup from the IK8 on my S5 with everything functional. The IK8 is definitely the better of these two watch phones though: better build quality, no buzzing during calls, better cell signal reception, better clock & launcher system, no dead zone on the touchscreen. Definitely not waterproof with the gaping hole of the microUSB port, but it looks not as vulnerable to a few raindrops as the S5, whose screen doesn't even seem to be glued tight.
For the rest I concur with Robson, very good loudspeaker, the GPS is indeed impressively good and seems better than on the S5, at the condition that one does the usual dance of enabling EPO etc.