I think that depends on the context in which you’re working. Flashes of genius don’t have much place an an enterprise code base. Everything is rigorously standardized and separated into layers. Each layer has a bunch of bookkeeping about dependencies, interfaces, mocks, expectations, and test cases. This is not really brain work; it’s typing. Now maybe if you’re really brilliant, you’ll do much better than average with the implementation of a really tricky layer. But the layers are rarely tricky, implementing them never takes all that much time, the slow part is always the integration and associated mocking rituals. Typing speed pays better dividends than brainpower in terms of productivity, there.