Piefed and Lemmy both intermix and talk to each other. What matters more is on the backend for mods and hosting communities. The big draw is Piefed has more features that help make moderation easier.

One thing on the user side that I like is how comments are handled. Since crossposting is common, Piefed allows you to see all comments from all crossposts as one thread so you don’t have to hop to the other post to see what’s being said. This is helpful if an article for example is posted to news communities on different instances.

The interaction limitation tho, I think that’s a bad call, even if it’s got an option to disable.