I've been researching the LGU2 a ton the last few days and you added a new wrinkle to my understanding.
I would only buy the watch if it works standalone, meaning I don't need to take my phone with me for the watch to work robustly.
If I understand you correctly, the watch doesn't need to be paired with my phone through BT (meaning nearby), but rather as long as the phone is on somewhere (could be 25 miles away), the watch and phone communicate, thus increasing functionality of the watch. Am I correct in understanding you?
If so, then, in my view, the watch is, for all intents and purposes, standalone (because the phone isn't in my pocket or even near me).
As a result, in the situation you describe, can it do the following:
1. Receive and send email through my Exchange?
2. Send and receive text messages through Google Voice?
3. Do navigation through Google Maps (though, I presume, not Waze?)?
4. Use Endomondo or other popular running/biking tracking apps?
5. Is there a calendar app on the watch that I can sync with my Exchange calendar? If so, which?
6. If not, can I access my calendar and get event notifications through this long-distance pairing?