The short answer
We thought Makapuʻu was absolutely worth doing. The trail is paved and steadily uphill, so it feels like a real walk rather than a difficult hike. It worked especially well because we were trying to fit a lot into one Oʻahu day.
The views are the reason to do it
The scenery opens quickly: steep sea cliffs, intensely blue Pacific water, offshore islets and the lighthouse below. The official trail is 2 miles round trip with about 500 feet of gain.
It is easy to fit into an Oʻahu itinerary
We did not want one hike to consume the entire day. Makapuʻu gave us a big scenic payoff without forcing us to abandon the rest of our windward-coast route. Parking was easy for us.
Know before you go
The route is exposed, hot and dry, so bring water and sun protection. The lighthouse itself is not open to hikers. We would stick to the official paved trail; the state says the nearby Makapuʻu tide pools are in a closed and dangerous area.
Our verdict
If you want a short Oʻahu hike with disproportionately good views, this is an easy recommendation. It is not wilderness hiking, but that is also what makes it so convenient.