Saves SO much time.
Its clear that the more information you can give it the better the results will be but even with a very loose description of what you're trying to achieve the results are a great starting point.
Only downside is that it can be a bit slow to load.
Bad. It just rephrased whatever brief I gave in a nice way. There are no detailed action steps or user stories. My GPT-3 trained chat does a better job. It can be used to polish a poorly written PRD.