David - I agree with your point; DMA is disabled with the Kinetic upgrade and the cards may perform differently on a DMA-enabled machine. I can see a case for repeating the tests on a DMA-enabled machine. I can aim to repeat this test when I've got the card and post the tests with DMA enabled; unfortunately my SA card is back in Notts and will take me a fortnight to do the test (unless someone wishes to post me instructions on how to temporarily turn a Kinetic into a normal SA card).
Steve. Hard drive stress is a very difficult subject. It's not the throughput of data which would shorten drives significantly; drive temperature and number of power cycles are the major factors. Having said that, DO NOT use drives for much beyond their warranty period - the consequences of having a dead drive are catastrophic.