Add me to the Jiko list. There is that basic choice between a buffet and table service (and like Ducklite, I always prefer table service) and the restaurant just seems a bit more "quiet" than Boma--always seems to be a low "roar" coming from Boma.
I imagine you've already checked out both menus and prices, but also would add that Jiko has an excellent wine list and several African beers which are pretty good.