128k will be fine, and is likely to give you slighly faster access times for small files, but really there is such a tiny difference it is probably not really measurable. when you look at the scale of possible stripe sizes, 4Kb works best for virtual memory, and 1024 kb + for video, you will see there is extremely little difference between the 128k that you have and the supposedly better 32k or 64k. When ever you do a rebuild leave a note to yourself to try the lower stripe size and see for yourself