Is the Dark Side of the Force more powerful?

I was watching the battle between Obi-Wan and Anakin in Revenge of the Sith, and it struck me that most of the time Obi-Wan was getting pushed back by Anakin, and he only really got the upper hand after getting the higher ground.

I later found that:

1. Darth Vitiate drained the life of his home planet


2. Darth Sion became immortal despite multiple mortal injuries and a broken body through his hatred


3. Darth Sidious could produce a hyperspace wormhole that could destroy entire planets


4. Darth Plagueis could apparently create new life from the force

Considering these feats it seems clear that the Dark Side is vastly superior in terms of power. However, Yoda doesn't seem to think so when he tells Luke in the Empire Strikes Back:

Luke: Vader... Is the dark side stronger?

Yoda: No, no, no. Quicker, easier, more seductive.