Marketplace should be used for all production downloads
The Universal Plugin Manager (UPM) or the Marketplace listing should be used for all production downloads! Compatibility information is provided to ensure the download is appropriate for your release.
The UPM available in your Atlassian product ties in directly with Marketplace to get the latest plugin available for your release. This is the recommended way to install and upgrade plugins.
SNAPSHOTS
Pre-release SNAPSHOTS or release candidates (rc) may be available for download here. SNAPSHOTS are work in progress used to gather feedback and deliver fixes prior to a production release. SNAPSHOTS normally pass regression tests, but new capabilities may not be complete or stable. Use with caution.