This is a RAM issue period. (Score 1)

His two complaints are one and the same: that OpenOffice uses more RAM than Excel. I have 2 Gb of ram in my machine, and his 16-sheet file loaded in one minute flat, not three as his benchmark showed. This is within 25% of the 47-second time that zipped MS XML loaded in Excel, which should be the most useful comparison since OpenOffice uses zipped XML as well. So, it doesn't seem there is a huge processing difference between the two engines; the difference is much more likely that he was swapping memory out to disk. My conclusion: Fix the RAM problem in Open Office and this issue evaporates.