Icons on the screen are Sir-Jony-Ive flat and there is a good feel to the user interface. Judging by a quick hands-on, the Android 4.4.2-powered gadget felt really rather snappy, and that’s down to its 2.5GHz ARM-compatible quad-core Qualcomm Snapdragon 800 system-on-a-chip processor. It’s clearly using the Samsung Touchwiz interface, too.Full details at The Register.
The big emphasis on fitness means that in addition to the supplied exercise encouragement app, the handset is ruggedized to the IP67 spec, which means its casing is better than splash-proof but it's not absolutely waterproof: IP67 means it's dust tight, and can withstand 30 minutes under one metre of water. Thus, it will survive an accidental dunk but don’t go swimming with it. More practically, you can use it as a music player in a steam-filled bathroom or go snowboarding with it.
Here's a hands on video from Android Authority: