I will stop uploading to any agency that I haven't been able to take a payout from after one year. I will stop uploading sooner to any agency that is overly picky about which of my images it accepts and/or makes the uploading task so arduous that it stops being worthwhile.
So far the following don't look like they will make the grade:
Bigstock and Deposit are definately on notice.
StockFresh I will cut a lot of slack to give them time to get up and running properly.