We have been using Fusion ERP reports for quite some time now and have encountered performance issues. Our long term strategy is to create similar reports in Fusion Analytics. Few suggestions to make this process easier for customers:
1) Provide a migration tool to migrate ERP reports to Fusion Analytics OR
2) Easy approach would be to provide Fusion ERP OOB reports (custom reports can be considered when migration tool is a viable approach) as canned visualizations within Fusion Analytics.