I've been a member of Stocksy since 2014 and recommend applying. It's definitely very difficult getting accepted at this point as they try to keep the membership numbers very low, but if you offer something unique, especially in the video realm it's not impossible.
Now in terms of royalties it is far and away much better than any microstock website. The minimum commission you make on a sale is $7.50 and it goes up from there, all the way up to $6000 (I've never had a sale that large, but consistently get ones for $300, $1000, and even the rare $2000).
They are also a co-op which means any changes to the operation of the site has to be voted on by the contributors ie; no surprise "hey we're lowering the prices of everything!"