I recently visited the Apple Store in toronto and looked at the Apple Watch and there is a classic glass watchface, so there is a layer of glass that adds refraction and reflection.
Retina displays on the new Mac Book Pro laptops have the display bonded tightly to the glass for less reflection and refraction—it does make a difference in the visual quality. Apple will get it right but I am thinking Apple is expecting cracked glass because you can use it on terminals and hotel doors for NFC interactions. This approach lets Apple replace the glass, if required.
The Apple Watch display is crisp, however, the default settings auto adjust the brightness of the Apple Watch display to slightly below the brightness you would expect from an iPhone. Colours are vibrant but it looks like Apple compromised on brightness settings to squeeze battery life. There may be challenges seeing the display in bright sunlight.
Below are some Apple Watch observationsand reviews I found online...
"iPhone service and repair website iPhonefixed earlier this week got its hands on a sapphire crystal Apple Watch display cover and decided to put the 38mm part through a scratch resistance test to weigh Apple's claims of a completely scratch-resistant sapphire display."
"The website ran the display cover through its test, rubbing it against a stone wall, scratching it with a coin, key, and abrasive paper, and finishing off with tapping the screen with a hammer and drilling it with a power drill. Following the tests, iPhonefixed found Apple's promise of a scratch-resistant display to be entirely accurate, with not a single scratch or scuff on the screen even after all of the site's attempts at leaving a mark."
"The Sports Edition will scratch. The biggest difference will be the screen, sapphire is much more resistant. If you are worried about scratches on the screen, go the Watch Edition with the saphire display."
I recommend spending the extra money and buy the sapphire displays (Watch Edition) because glass will never be as scratch or shatter resistant as sapphire. The Ion-X glass Apple uses in the Sports Edition Apple Watch is less likely to survive the abuse of NFC tap interactions (Apple Pay, Hotel NFC keyless entry lock surface, etc.)
THE GOOD: The Apple Watch is a beautifully constructed, compact smartwatch. It's feature-packed, with solid fitness software, hundreds of apps, and the ability to send and receive calls via an iPhone.
THE BAD: Battery barely lasts a day and recharge time is slow; most models and configurations cost more than they should; requires an iPhone 5 or later to work; interface can be confusing; sometimes slow to communicate with a paired iPhone.
THE BOTTOM LINE: The Apple Watch is the most ambitious, well-constructed smartwatch ever seen, but first-gen shortfalls make it feel more like a fashionable toy than a necessary tool.