Writing this review from a trail runner's perspective rather than a hiker. I had a great time running the north side Kaena point, it has lots of things to challenge you: Rolling hills, uneven rocky terrain, loose sand, hot scorching sun. I highly recommend running an hour before sunrise to beat the sun, otherwise you need to have sunscreen, shades, and a hat/visor to protect yourself. North side is definitely underrated.
If you do just the flat straight part, it pretty easy.
But be forewarned, it's a very hot hike.
If you find your way up the mountain to the old pillbox stuff, it can be worth it.
For some reason, all my mainlander friends want to take this hike.
My recommendation when to make this hike in the dead of winter when it gets below 90°.
I carry a travel umbrella to carry as a parasol on the way back as my brain slowly cooks.
If you have the wind to make it up the mountains, on a clear day you can see forever.