I've been through conversions of millions of documents. If your focus is records management and retention (not heavily revising or creating new documents from old documents), I suggest converting Notes documents to a static, fixed content format while in the native Notes environment - like take them to PDF files. Then, extract and attach or associate typical Notes document level metadata (create dates, modified dates, creator, source database, conversions dates, etc.). Of course, add meaningful documents fields/metadata.
The goal is to end up with both a rich visual representation of the documents (rich text, etc.) as well as a rich metadata representation. If you use much Notes rich text you have no chance of ever getting visual fidelity once you leave Notes - so build the final doc in there.
After that, send the files to the appropriate Alfresco folders and let the index engine do its thing on both (fixed) content (pdf) and the structured metadata fields. This will give you rich searching by metadata and/or content.
Finally, consider exploiting the Alfresco RM features by including disposition/expiration, etc. as part of the folder/document properties. Most likely, the documents are already at different points in their retention lifecycle so that should be preserved on a per-document level.
How many docs do you have to convert?
