Fence vs. Underground Fence vs. Halo/Spot-On

Looking to get other opinions from those with the breed.

We have 15 acres and live in a place with okay-ish service (ATT).

A real fence is my ideal situation, but fencing a total of 15 acres with most of the property lines being heavily wooded is going to be very expensive & time-consuming.

I’m unsure if you can even do an underground fence with this much property. I don’t know much about these.

Thoughts between Halo & Spot-On? Is one better than the other?