Latency. Lower is better. The fiber connection will be a fraction of the SL link.
It matters. Low latency bandwidth is more responsive.
Of course, the likely deciding factor is going to be the $$$, as it always is...
Another option would be a point to point wireless link, using carrier-grade gear. Set up an AP at the road, power it with a small solar system. Client at the far end.
This kind of stuff:
The Ubiquiti airMAX PowerBeam 5AC 500 mm Bridge US [PBE-5AC-500-US] is a 5 GHz WiFi antenna with a 450+ Mbps Real TCP/IP throughput rate.Using airMAX 802.11ac technology, this kit supports up to 450+ Mbps throughput in a small form factor. It launches with PtP functionality, however client mode...
shopdoubleradius.com
This would (should) have the benefits of the all-fiber drop without the expense of a 1400 ft cabling run.