Robert,
From what I have read, if you are getting sweet tasting onions, you probably have low Sulphur soil as they do in Vidalia, Georgia.
Let us know how your 1015Y storage life test goes.
I have about 18 of the 1015Y in a seedling tray awaiting transplant into an EarthTainer for trial before I do the real September starts in about 7 weeks:
regards,
Raybo