I personally run Double Monkey's and let me explain why:
It has no DR's in this bracket with anything else. People argue that the .5 second cast time makes it impossible to get it off when you want it. I never find this an issue, a hunter should know the damage he/she can do, thus being able to read the situation accordingly to compensate for any "delay" your stun might yield. 95% of the time my pet blind goes on my focus target, with a non DR'd scatter right after. It's a ranged stun, so a simple macro telling your pet to cast dash before using pet blind helps a lot.
I run 2 because both stuns are on 2 separate CD's. I dismiss/re-summon accordingly to provide teammates with pet peels, and Roar Sacs, and still maintain the hunter damage we all fear.