And if you just use the gps without the e-sim. You still get the same functionality like calls etc if you just pair it with your iPhone via Bluetooth.
I’m guessing the e-sim just gives you the flexibility of not having to have your phone with you all the time although my phone never leaves my pocket so I reckon the cellular part would be a waste of money for me.
Bingo! If you have the regular one and you have your phone with you, you can still answer calls on your watch. I've never bothered with the cellular version for that reason, my phone is always with me!
If you were a runner or something I can see why the cellular version would appeal as you'd be able to still call and stream music.