1. Battery life: I wake up at 6 and go to bed at midnight. The bigger battery, and the transreflective display gives me some peace of mind that I'll not worry that my smartwatch will die when I need it. Also, love the idea of monitoring my sleep and setting an alarm to wake me up at the ideal time (instead of being in the table recharging).
2. Square display: Although round watch faces look classy, I don't like the idea of wasting screen real state for a fancier look.
3. Android Wear: Definitely Google got it right (Unlike Samsung or Apple). A smartwatch complements the smartphone (not replace its features). Simplicity to dismiss discretely notifications, or get directions while using the smartphone for other purpose, or keeping it in your pocket whithout the hassle of picking it up every time I get another notification.
4. Display: As an Ingress player, I'm frequently outside. Sunlight can make most screens difficult to read, or waste too much energy to give maximum luminosity. Transreflective display uses the ambient light, making it perfectly readable at direct sun light and saving energy.