As an unscientific piece of data, I recently filled my S30 with observations. About 50GB worth of storage used. The jpg files constituted 6gb. I agree it would be nice to eliminate the generation of these interim JPG files, but not sure it would accomplish a lot from a storage perpective. Still, 6GB is about 12 per cent so its not nothing. Not sure how this would affect FIT file collection performance (that is, more time spent on generating FIT files)......