AKL = yes. I think it's definitely worth a trip over there (it's not THAT far) to check it out. It's my favorite resort!
Jiko = eh. We really liked the appetizers, and it's a gorgeous restaurant, but we've never been particularly impressed with our entrees there. On our first visit there, we did try that pistachio creme brulee with the surprise at the bottom (spoiler: hidden chocolate!), and it did not disappoint.
As far as the signature dining places we've tried, Jiko is at the bottom. My hubby had THE filet, and was not impressed. I had the vegetarian entree and it was not only not good, it was poorly cooked. Jiko generally gets good reviews, though.
If I'm headed to AKL, I'd rather go to Boma, and I'm not a fan of buffets. Boma is in another league, though.