Hi @stuartv , there are a few differences.
The screen protector will get scratched, whereas the sapphire crystal will not. Shearwater is using low-quality screen protectors, and therefore owners can expect more scratches and need replacement protectors more frequently.
The Tern screen protector is also poorly designed, as it obscures the display labels for the buttons and there is a gap allowing dust and dirt to become ingrained between the protector and the bezel.
The other difference is that the Teric's sapphire construction has better viewing angles and optical clarity than the Tern.
Regardless of whether these issues matter to you, it is inexcusable at this price point that the Tern does not have a sapphire crystal. As I previously mentioned, sapphire crystals can be found on very cheap wristwatches.
