I have done a good bit of trial and error here
This an example screenshot of the sort of complexity in my database
In all there are about 18 fields, of which about half are hidden with underlying formulas.
My back of napkin conclusion is as follows:
0 to 1,000 records: No issue
1,000 to 5,000 records: Takes progressively longer to load the document but has mostly decent response time once it is loaded
Over 5,000 records: Not feasible
I faced the dilemma that I do have data tables substantially over 5,000 records, but I also really like the Coda format for organizing the document. My solution was to use MySQL for the data and then embed the resulting report into Coda using a neat MySQL front-end:
I can share details on the MySQL process if you are interested.
Bottom-line - Coda has no equal with regard to document presentation, but it has only very basic database capabilities. But the new embedding and document sharing capabilities make it easy to get a great outcome by using different software packages for the jobs they are each best at.