However, if you were to ask me to choose between my immersion circulator and my steam oven, I'd have to go with the immersion circulator.
I'm thinking about upgrading my old convection oven to a combi. I have read a lot of posts, and one of my main doubts was precisely what you mention: Does it make any sense to spend the money in a combi provided that I already have a sous-vide immersion equipment and a Thermomix which includes a steamer to cook vegetables, ...? I think it does not make sense.
I have read Modernist Cuisine and I have not seen any example where wet air is needed beside fish or vegetables low temp steam cooking. The only exception I'm aware o combi baking is bread, and in this case humidity is only needed the first 10-15 min, which can be attained putting a tray with volcánic stones in the bottom of the oven and a adding boiling water to the tray just before start baking the bread.
Does your experience confirm my impression?