I used to Wonder Trade a LOT. Spent hours every day doing it to get all sorts of IV bred Pokemon and other rares. I got My Tyranitar who not only has 6 Perfect IV stats, but is also shiny from Wonder Trade.
These days, I don't do it. Like at all. For any reason. I used to Wonder trade for the free rare candies to level up my monsters to level 100. Now that ORAS came around, and allowed me to level my monsters to lvl 100 in 15 minutes, why do I need rare candies? I just release my bred monsters instead. I must have released like 100 Snivys, 60% of them had the hidden ability. Many of them had 4 or 5 perfect IV's.
Why did I give up on Wonder Trading? Because of the crap people dump in Wonder Trade. Why toss around my Hidden ability IV bred monsters just to get back level 3 caterpies, pidgeys and bidoofs? Maybe every one in a while, I get something. But nothing worthwhile. I can breed anything I want, and have plenty of nearby friends to get HA monsters. People need to stop playing hot potato with Pokemon, and only put monsters worth something.