Hi Walter,
My advice to you would be to use the Tamino API for Java. The main reason is that at some point in the future I suspect the HTTP client API will be deprecated.
The Tamino API for Java has a more flexible architecture for supporting different object models, e.g. JDOM, which the HTTP client API does not. As these core API’s are enhancements or new things come along the Tamino API for Java will be enhanced to incorporate them.
For the performance question: I think this is not easy to answer because the new API supports newer core API’s and has a completely different architecture. So its not so easy to compare the two as they are very different. At the very core of the API it is still HTTP communication and the performance there won’t have changed.
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