Native support
Doug explains how Swiftstack has native support for Swift while everyone else emulates it. We at Cloudian agree and if your requirements is only for Swift then they are a great choice.
Doug then also states that S3 is the de facto standard and once again we agree. We estimate there are 4,000 apps on S3 and well lets just say not that many for Swift!
Doug then says everyone emulates S3 and here he is wrong. Cloudian uses the S3 spec as our API. We don't emulate S3 it is how we control our system. To use Doug's terminology in the same way that Swiftstack is native for Swift, Cloudian is native for S3. If you believe Doug and Cloudian that S3 is the de facto standard for object then you should be looking at a native implementation ie Cloudian.
All other vendors need a connector or translator to go from S3 the their API. Cloudian does not as it is native S3 and that is why we have full compatibility. We challenge any vendor to come forward and let an independent analyst test our respective API's for S3 compatibility.