The biggest change between the new handset and the original M8 comes in the rear camera. Whereas HTC opted for a 4 megapixel "Ultrapixel" shooter on the the older handset, the M8s is fitted with a more conventional 13 MP F/2.0 camera. The front-facing shooter sticks with the same 5 MP resolution as before.
The other big change from the M8 to the M8s is that it switches to an octa-core Snapdragon 615, with four cores running at 1.7 GHz and four at 1 GHz. The battery capacity has also been upped from 2,600 to 2,840 mAh.
Elsewhere, it's more of the same, with the device offering 1,920 x 1,080 spread out over 5-inches, like in the M8 and M9. In terms of design, the handset looks identical to the One M8. It offers an all-metal construction, runs on Android 5.0 Lollipop and packs 16 GB of expandable internal storage alongside 2 GB of RAM. There are also a pair of the company's impressive BoomSound front-facing speakers on board.
HTC says the new handset will launch in the UK this month for £380 (US$564). Considering you can probably find the original One M8 on sale for less than that, it will be interesting to see how HTC brands this one. It could end up being a limited regional release, as there's no word on a US launch.