Steve,

The intent of the 4 blade X prop was to increase the efficiency of each blade. I can't remember the exact size prop Chip had on his. It wouldn't be anymore than about a 18-19" blade. It's quieter on the ground when you run it up. In the air it really didn't sound a lot quieter, and it doesn't have as much performance as the 2 blade setup. Not the best prop for windy conditions, but it looks cool!

Sounds good Chris.

Later