Bought the Apple TV 4K  from iStudio at Changi Airport’s Terminal 2 when I was heading to South Korea. In Singapore, the Apple TV 4K retails for S$268 for the 32GB and S$298 for the 64GB.
Since I bought it within the airport’s departure area, I don’t have to pay the extra 7% GST, and hence the Apple TV 4K cost me S$250.47 for the 32GB.
The Apple TV 4K was officially launched in the US on 22nd September 2017 after it was unveiled at the Apple’s September 12th event.
I didn’t have the exact date when it was launched in Singapore. I heard it was around the second week of October 2017.
In terms of design, the Apple TV 4K is almost exactly the same as the Apple TV (4th Gen) . It even measures the same (98mm x 98mm x 35mm) and weighs the same (425g).
The only difference is the Apple TV 4K doesn’t have the USB-C port at the back which Apple says is for service and support.
However, the internals of Apple TV 4K is different. It features A10x chip, 3GB RAM, HDMI 2.0a, Bluetooth 5.0, Gigabit Ethernet and simultaneous dual-band (2.4GHz and 5GHz).
In contrast, the Apple TV (4th Gen) uses an A8 chip, 2GB RAM, HDMI 1.4, Bluetooth 4.0, 10/100Mbps Ethernet and doesn’t support simultaneous dual band.
If your television supports HDR10, you will be glad to know that the Apple TV 4K supports it as well.
The Apple TV remote also received a minor cosmetic upgrade. There is now a raised white ring around the menu button so you can press the menu button easily without looking. Other than that, nothing much has changed.
I will be replacing my living room’s Apple TV (4th Gen) with the Apple TV 4K since my living room’s television supports 4K.
The Apple TV (4th Gen) will be moved to my master bedroom since my master bedroom’s television only supports 1080p and I will deprecate my Nexus Player in my master bedroom.