From what I read 50 is soupposed to stick around. In the article I read said it was to give velvia lovers a faster velvia while keeping the orignial as well. I'll find the article Monday for you, it's at work.

I will be posting a roll of the velvia 100F I shot towards the end of the week. I have to mail it to a lab and mailed back.

I have heard some say they could have used provia with the same results. So I'll just have to wait and see.. Wish I could have been of more help.