The current trunk version of fpspreadsheet contains the speed test application posted here by rvk, thanks a lot (folder examples/fpsSpeedTest). I modified it to allow changing of parameters (number of rows, format seletion etc. - they are stored in an ini file) and added also a routine for reading speed (not fully complete).
I extended the BufStream to be usable for the spreadsheet readers as well (all xls, ods, but not xlsx which does not have a reader at all so far). A factor 3 speed improvement for reading of biff2 compared to a few revisions ago. But I am not quite satisfied with this improvement because biff2 still reads considerably slower than biff5 and biff8 - in fact, if I copy the biff2 FileStream to a memorystream I get the same speed as for the other biffs, so something must still be wrong with the BufStream...
VirtualMode is not yet implemented for reading, but will follow.
Due to these modifications the workbook's "WritingOptions" are no longer named appropriately, and I renamed this property to "Options", and the set elements have the prefix "bo" ("book options") now (instead of "wo")