We agree with you that currently the documentation regarding the report designers may be confusing and we have already took some actions in making it more clear. The documentation update will be published with the Service Pack scheduled for the next week. In the meantime here is a small part that may help you in making in your report designer choice:
Generally the report designers have common code base and most of the features are supported in the both report designers.
The report definition is designed in a report designer. We provide two report designer options. Both report authoring environments include features such as aggregates, enhanced support for expressions and wizards for creating graphs, maps, crosstabs, tables, band and label reports.
In the following list you can read about the report designers main differences:
Edit: The latest information about the designers differences is available in the Report Designers help article.
Let us know if you have any questions or if you need additional assistance for your evaluation.
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