Do you mean the TS Yak & Yeti dinner? If time is not an issue for you and you don't mind doing 2 sit down restaurants in one day, one for lunch & dinner, I would do Kona lunch & yak & yet dinner. Yak & yeti TS food is way better than their QS food. However having that said, their QS isn't bad either. I would do what works best with your schedule.
Yak & Yeti QS isn't anywhere near what the TS offerings are. For the TS restaurant, you could get items such as duck and whole fish that are somewhat rare to see, on most Disney TS menus! (That's what I liked about it, BTW, the duck.)
Another thing to note is that Y&Y lunch and dinner menus are the same, where Kona Cafe's lunch and dinner menus are different. We've done Kona for dinner twice and loved everything we got (steak, noodles, duck...) so if either menu speaks to you more and you have flexible scheduling, keep that in mind!
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