SwiftData + public CloudKitDatabase?

How does the performance of SwiftData + CloudKit private database compare to CoreData + NSPersistenceCloudKitContainer?

They are analogous. I think generally speaking SwiftData has different performance patterns than CoreData, but the CloudKit sync is identical between the two.

Also, will SwiftData + CloudKit support the CK public database, in the future? Thank you!

That's worth a feedback report. I think the details we'd like to understand in your report are:

• How do you intend to manage access to data? Can you use case support all of the data being resident on every customer device?
• What are the ownership expectations of your customers when they contribute data to the public database? i.e. will they expect to be able to edit any record in the database? Or just their own?

Users would have read only access to the public CK database. They would generate their own results, based on public data, and save them to a private CK database.