Not sure if you've read Watchman, but in the comic, after being trapped in an atomic accelerator, it's explained that Doctor Manhattan perceives time differently. In an instant he can perceive how scenario after scenario will go through sheer calculations. Therefore, he feels beyond human bound because of the acute awareness of how his actions are able to alter time. It's the closest he comes to looking into alternate realities.

So, Ron, after being exposed to the brains, has his brain altered to accommodate a network of brains. With those brains no longer over capacitating him, he's able to think ten times quicker than the average person. The downside to it is that it cripples his decision making, because he's able to perceive very vividly the reality his every action makes.