I have been told the same and did try three blade and four blade Muzzy's. Although, I was not comfortable with the Muzzy, I went with G5 Montechs and NAP Crossfires, the four blade did fly a little better. But, the fourth blade adds additional surface area for the wind, etc. to cause planing. That said the 4 blades did fly more consistent than three.
Also, the 4 blades go together differently than the 3 blades balancing the head a little better. In fact, slick trick heads are a 4 blade fixed that go together in a similar fashion. Slick tricks claim to have field point accuracy and those who have used them say that's true.