If you want Hawaiian, go to L&L, Ono's, or Aloha Kitchen. True island flavors are more complex than this and not all based on coconut, corn syrup, or sacchariny-teriyaki.
I'd been eyeing Rumbi for a while and was psyched to try it out. I ordered the chicken rice bowl with the recommended "Rumbi rice" and I really couldn't finish it. I felt bad too, because someone paid for me, but it was really unremarkable and I didn't want to take it home.
The chicken was rather dry, the veggies were not fresh or crispy al-dente, and it was topped with a sauce that was way too sweet. The "Rumbi rice" was a low-grade quality rice with some beans and drenched in very sweet coconut milk/sauce. And it was expensive. My dining partner had the same thing with brown rice and we both had drinks. Grand total was just under $25, which was a bit steep for a poor stir-fry and fountain drink x2.
The service was friendly, however. So plus one star.