Looks like a high standard and not for most of us peons
Notwithstanding the high standard, I suspect you will find similar on cheaper sites but without the same digging needed
Can't see too many shopping there for their blogs
Better than average chance that many of the selected contributors will need other homes for a fair percentage of their images
Subject matter coverage is limited
In most areas of commerce there is the high value low volume market as well as the low value high volume so wish them well

First look at Stocksy...

It is exciting to see a co-op finally come to market, but otherwise, it's a little disappointing.

-- It looks cliquey, a bunch of friends getting together, and compromising their editorial standards in the process. Editing is weak, too many similars, and uneven standards of acceptance. I would reject more than 50% of what's there if I were one of their inspectors. They need to take care, there's an earlier echo of this problem at iStock itself, it's being repeated.
-- Mostly it looks like a collection of Vetta and Agency quality material. On the Agency front, we're looking at top of the range microstock, but it's still microstock. People smiling at camera or doing very obvious things, literal tropes and formulas employed.
-- On the Vetta side, we see works that reach the half way mark, quality executions in search of a concept. The authors are in too much of a hurry to create cool shots. Self-editing is weak, as is conceptual self-understanding, planning and preparation.

So I think we're still waiting for the holy grail, a new agency styled as a co-op, targetted not at designers but at art directors, with old Taxi type quality. Clever, unique, strong concepts, the kind of work the best assignment photographers produce, or used to produce before Getty largely lost their form.

Good luck, Stocksy, here's looking forward to your evolution and improvement.

I know little about Stocksy, but if they have image exclusivity and many of the best photographers put their best images there (and only there) because they get a good return, then I can imagine buyers might be interested.

That policy sure feels crazy to me.

Example:

I have a friend that really doesn't want to appear in any sold image with his face showing.
I have a release for a image with him his face masked. I use my own release with a shoot description, but there is no field for shoot description in DS's own MR form.
So if I would be "idiot" I could sell all the fun/artsy photos we have shot with the guy since i have the one release from year -1. All released in DS.

The example might be far fetched, but why refuse several releases? What harm does it do to allow more than one release /person?

HDD space comes in to mind, but it's like "a fart in the desert" compared to the HDD space all the images use.