I need to connect two Ethernet cables together. Right now, neither end is terminated. I think my two options are to either terminate both ends and then use something like this RJ45 Coupler F/F Straight Connector, or to just strip each wire and join them, either by twisting or soldering them together. Is either way clearly better than the other?
CAT5e/6 junction boxes are available for splicing cables without needing to terminate, twist, or soldier.
Junction boxes are better for permanent cabling, as they're more secure than terminated ends paired with a coupler, or twisted/soldiered. Cables with these junction boxes won't be pulled apart at the splice point, unlike with other splice methods.
Note: I've never actually purchased from any of these particular storefronts. I'm simply linking to them to show examples of junction boxes.
In a pinch I've been known to strip it, twist the inner wires together together, and wrap with electrical tape. Its a ghetto soluton, but effective if you do not move the cable around to much. That being said that coupler is like $2 so it seems like you have several good options.