Hmm.. I think your update system is not efficient, to many old files..
I don't know either, are all files changed? if no, why not make update just for new files or files that should be replaced?
for handling new blogger, of course there is the one which contains all files needed.. but for people who just need to update, I think its more efficient, less file, less size on zipped file, less upload, less time, and less error..
correct me if I'm wrong..
thx, and regards
sorry for bad english