All things being equal a three way is better than a two way, due the three way not sharing mid/bass range in a single driver. But this not the end of the story, driver selection, crossover design/integration and cabinet construction also are important in overall sound quality. And as mentioned by MceLjo, amp choice is also very important, why have great speakers if they are under driven by the amp?
two way v. three way speakers
I recently heard some magico mini's at a friend's house. They sounded amazing. And they were 'only' a two way speakers, but they filled the room with amazing sound. So now I wonder, what does the additional driver add, especially when it is the same size as the second driver. For example, the SF Olympica III's have two drivers of the same size. I know that third driver adds a lot to the price, but what does it sonically? Thank you all in advance.