Oh, how I disagree with you. While having theatrics being a part of some songs gives it more appeal, it isn't the case with a lot that he has done, especially the latter part of his career. I even posted about this before. More recently, listen to the reaction from the fans as Bowie steps up to do 'Life on Mars' from the Fashion Rocks show. By that standard, the fan reaction is something a live version lacks and even gives you the thrill of hysteria you can't get from studio versions. The energy feeds his performance as you can see from the fabulous Arcade Fire collaboration he did at the same show.
To go further in time, I think his Saturday Night Live version of 'Man Who Sold the World' with Klaus Nomi is a great representation at what you can do with a one-off live performance. Though the theatrics of that one is great in its own right, if you were to hear it without the visual, you will still be captured by a breathtaking performance.
So, yeah, I disagree. Anyway, don't you think 'Hallo, Spaceboy' is a testament to a better live version than studio?