It's family style, so rather than choosing off of a menu, your food is brought to you from a menu. Same deal at the Luau. It's unlimited food, but the reason we don't like it is because choices are limited. Here's a
menu for Ohana. As you can see, there is only one dessert option. More power to you if that's what you would like to have, but by comparison, here's a
menu for Kona. As you can see, the menu has a wider variety. It's also cheaper to eat at Kona than at Ohana. Kona will cost at most $30 per adult while Ohana costs at least $30 per person (I'm not sure of the exact pricing). Don't get me wrong; some people love Ohana, but not worth it IMO.
Boma is a buffet with African-inspired dishes. Because it is a buffet, it'll be about $30-36, plus the cost if you decide to order alcohol, but IMO it's much more worth it to spend the money there than at Ohana. There's a lot more of a selection, and the prime rib is fantastic (as is everything, but especially the prime rib). I think that's where you mean with the steak and mac and cheese. IDK, I only eat Mac and Cheese if it comes out of the blue box, lol.
In the end, of course, it is up to you. That's just my advice.