I'm a little biased because I work at Postman, but I've also used RapidAPI in the past. It won't matter which OpenAPI editor you use, or even if you develop the OpenAPI spec on a third-party platform besides the ones you've mentioned. But I find the automation in Postman far easier to use, and being able to publish your API afterward to everyone makes it a lot easier to let devs find your API and use it right within Postman immediately. The auto-generated docs, the auto-generated client-side samples, and for a handful of languages we even auto-generate some server-side code too.