Vancouver is a beautiful city - you should plan to spend time there, especially in the summer.
Also - cruises are the best way to really see Hawaii, also. You get to see each island and have a hotel room that travels with you.
By the looks of it - both itineraries are very similar since Kona and Hilo are both on the Big Island. You get overnights on all three islands, pretty much the same as POA.
When we went to Honolulu we made the mistake of renting a car and trying to navigate on our own to the North Shore. We got caught in a bad traffic jam for hours. On the return after the cruise some friends picked us up and drove around (literally) the island - and we saw so much more.