If you want to see all the islands do a cruise, it's way cheaper and it's basically your moving hotel, plus food, my wife and I had a blast, it leaves Honolulu for Maui and you're there for 2 days, we rented a Jeep for 24 hrs while we were in port, then it hits Hilo, then Kona, then to Kauai for 2 days, then back to Honolulu where we stayed in Waikiki for another few days before coming home
We did everything while we were there too, a real luau, climbed diamond Head, snorkeled Molokini Crater with huge sea turtles, rented scooters in Kauai, did our own Road to Hana in the jeep and stopped where we wanted to, did helicopter ride and saw the lava flowing into the ocean, walked thru a lava tube at Volcano National Park, went on a hike thru the jungle to waterfalls, went to Pearl Harbor, drove up to North shore and went to Waimea Bay and Waimea Falls (no way Waimea is bigger than Bells Beach brah!!!!), ate at Shrimp Trucks, we had an absolute blast
we're going again in 2-3 years but only going to Maui and Oahu, once you've seen the other 2 islands no use in going back IMO
I got hit with jet lag on day 2 or 3 and it kicked my ass, so be careful what you do on day 3 (I'm on east coast)