* The 245 locks GPS really, really fast. I never have to wait for it. Much, much faster than my older 630. The Apple Watch doesn't even tell you if it has locked a signal. I think it would lock fast if I had my phone with me, since it would use the phone's GPS to save watch battery, but I think it would be confused if I left my phone in the house while stepping out the front door for a run.
* The 245 has physical buttons that reliably work with sweaty fingers in the summer and with gloves in the winter. So many times I couldn't stop a workout on the Apple Watch because of the swipe needed.
* Display is always on, no need to raise my arm directly in front of my face to turn it on. Too many times I had to raise or twist my arm multiple times to see my pace with Apple.