I made the switch from many years of HH Diamond to MR Plat several years ago and I'm happy I did. The major factors in switching were the HH devaluation that happened in that timeframe, the lack of a lifetime elite program with HH, and limited HH properties in places I like to travel.
My calculus for MR points earnings on a two night $140 per nite stay is:
Base Points: 2800
Platinum 50% bonus points: 1400
Platinum Arrival Bonus: 500 (may vary depending on property type)
MR Visa points earnings: 1400
Total is 6100 points, however, with MR promotions I average roughly 1500 points per night extra earnings so the real tally is about 9100 points.
IMO one HH point is worth about 0.7 cents while one MR point is worth about 1.2 cents so comparing point earning abilities between the programs doesn't give you the complete picture. You can always do better than those metrics depending on the season and the property but those are my averages. With elite bonuses and promos factored in my take is that the return on paid stays is better overall with Marriott than with Hilton.
My strategy has not been a total break from HH. I have an HH Amex so I get gold status and continue to slowly earn points for occasional stays at HH properties that I like. I also have the MR visa and that helps with MR elite nights.
I love vacationing in Hawaii but stay away from Oahu.
For the big island you've got the Hilton Waikoloa and the Marriott Waikoloa next door. Both very nice properties but I'd give the edge to HWV. There's also a CY in Kona.
For Maui you've got the Grand Wailea with HH and several Marriott properties. At the high end there's the Ritz which is excellent but pricey points wise. For points value and quality I'll take the Marriott Wailea every time at 140,000 MR points for a 5 night stay (much better redemption value than the GW IMO).
For Kauai there is a FS Marriott in a very nice location, but the property is a bit dated. There are four other MR properties with three being Marriott Vacation Club types. No HH property on Kauai.