I've never done this specific itinerary on HAL, but did the identical thing on Princess. I've also done two Hawaii/South Pacific voyages on HAL.
It's a great itinerary IF you like sea days. If you don't, then don't bother.
You will have a full four days at sea heading to the islands. You will then have five days in the islands. You will visit Kona and Hilo on the big island, one day each. You will also visit Maui, usually for a full day lasting well into the night (like 11:00 p.m.). Then you've have a day on Oahu. You will then either day a day on Kauai, or a second day on Oahu. Finally, you will have five more days at sea, including a "service call" stop at Ensenada to satisfy the requirements of the Passenger Services Act.
As you can see, you will have more days at sea than anything else.
Now, in my case, I LOVE days at sea in which to enjoy the amenities of the ship. But some people have a problem with them, and they tend to get bored (though I can't imagine how).
So, evaluate your desires for a trip to Hawaii, and if you decide that you like extended days at sea, then I can't imagine a better cruise line to take this cruise with, because their ships and service are a cut above what you generally find on most of the other cruise lines.
kryos says it best. i've done the voyage on HAL twice, once on statendam and last november on the zaandam. fabulous, but it is mostly an 'at sea' experience. i, too, love sea days; they force me to do next to nothing, which i need in my life. but,, some souls on board were going crazy by the time we got back to san diego. if you love sea days, it is just heaven, and on HAL if it is chilly outside and you want to swim or do the hot tubs, there's that great covered lido pool. enjoy. padre hombre
ps. at the final sail-away, the tossing of the leis ceremony will forever make you want to come back.