Here's how I understand stipping at the simplest level...

If the OS requests a 64K chunk of data from disk, this is what will happen with various stripe sizes...
16K stripe = each disk has to seek and deliver two 16k chunks of data
32K stripe = each disk has to seek and deliver one 32k chunk of data
64K stripe = only one disk will have to seek and deliver a chunk of data

Now, with magnetic storage, the 16k stripe is inefficient because each disk has to seek twice. The 64K stripe is not ideal either in this example because you are not gaining any parallelism from this data fetch. The 32K stripe is ideal in this example because you are maximizing parallelism but each disk only has to seek once.

If you take the seek time out of it, then there is NO negative effects with going with a smaller strip size and the benefit is that when the OS requests smaller chunks of data, you will gain the benefits of added parallelism.

A 128K stripe makes no sense to me at all because it means for almost all small data chunks requested from or written to disk, only one disk will be working and you are not gaining the benefits of paralellism from striping across drives. Such a large stripe size would only make sense if all of your data requests are significantly bigger than 128K.

What's flawed with my thinking?