Personally, though, I don't see them as at all interchangeable. While Boma is good for what it is, it isn't just a less expensive version of Jiko. Jiko is among the very best dining experiences at WDW.
My DW decided Boma over Jiko for our coming November trip. Haven't tried either, but figured with Boma we could try a lot of things.
Dr. E
I've done both a couple of times and you can't really compare the food quality. If you are interested in quantity and variety, then Boma fits the bill. We enjoy it but its not fair to compare it to Jiko.
I would order: Fillet of Beef with Mac and Cheese at Jiko. And a desert. This would cost me 2 TS credits per person
Boma: I will sample a few nice salads/appetizers, the FANTASTIC soups. Enjoy a delicious chunk of Prime Rib done perfectly, have some lamb, some chicken, have SEVERAL helpings of the "to die for" sweet potatoes. And top it off with a desert. This costs only 1 TS credits per person.