Are the reports generated from stored procs or direct joins to the DB tables?
Just wondering, because if the report joins to the table(s) it could be dealing with filtering a lot of data out, but a stored proc would do that, and perhaps more effeciently as you can specify the joins and reduce the number of records for each step, and your SQL software is optimized to perform such operations (use each software to its strength).
If the report is already coming from a stored proc, does it significantly longer to just run the stored proc than to create the report (after all if the stored proc takes 5 minutes to run, report is not going to be any faster) in which case, the goal would be to speed up the stored proc (just did this myself after a yr of putting it off...so much faster, was worth the effort).
I know I didn't answer the original question, as I really don't know...my concerns are usually about getting the data as fast as possible, CR creation/formatting of the report is something I really haven't bother with (and some of my reports are 1000s of pages, but they don't take too long to retrieve)
HTH