- podman having a more consistent CLI API/more parameters (but I think docker did at least partially catch up)
- user-ns container allow mounting the context instead of copying it, this means that if you somehow end up with a huge build context user-ns build can be _way_ faster then "classical" docker builds (might also apply to rootless docker, idk.). We ran into that when that one person in the team using Mac+Docker asked if we can do something about the unbearable slow docker build times (no one else on the team experienced :/)
- docker implicitly always has the docker Hub as configured as source which resolves "unqualified", this might not be true for your podman default setup so some scripts etc. which should work with both might fail (but it's easy to fix, preferable always qualify your images as there are increasingly more image hosts, in worst add docker hub in the config file).
- "podman compose" supports some less feature, this might seem like a huge issue but compose doesn't seem the best choice for deploying software and if I look how it turned out in dev setups the moment things became larger/more complicated I came to the conclusion that docker/podman compose is one of the easy to start with then get trapped in a high complexity/maintenance cost "bad" corner technologies. But I'm still looking for alternatives.
- podman sometimes missing some resource management features, but also docker sometimes does have differences in how it effectively enforces them not just between version but also with the same version between OSes, this had lead to issues before where docker-rootless kills a container and docker on Mac doesn't because on Mac it didn't notice spikes in resource usage (in that specific case).