For the generic average dev pushing SaaS features, it's way faster. For the kind of stuff where the coding is essentially all boilerplate/connector, something like Claude shines. Because there's already a pattern for everything in the codebase.
If you are able to parallelize your work, e.g. work on 2 or 3 features at a time, your coding time goes down to essentially zero, or rather the time it takes you to write the prompts (hint: use dictation if you're working from home), and all your work is now spent on all the same design and manual testing you were doing before. So depending on what proportion of your time was spent on design/testing vs. writing actual code before, your generic/average dev can see a productivity boost of anywhere from 2x to 20x. It really just depends on what proportion of their job they actually spend literally writing code.