I'm very pleased with Panthermedia, I have had four sales and 8 referral sales. I have earned more money here in a quicker time than a whole bunch of "other" newer sites.
I get either the editors tip or recommends on all my images. With the site being new to me, I have put time into looking at what the front page photo styles are and learn by it.
Overall I regard it as a worthwhile experiment and continue to upload to them.
Here is my referral link to
PantherMedia for anyone wanting to give them a try.