Pretty, we like it. It does take a bit of a breeze to get both blades really spinning. In a gentle one blad may move slowly while the other barely moves or remains at rest.
My neighbors cal it a hurricane detector. If only 1 blade is spinning, we have a tropical breeze, if 1 moves and the other barely moves, we have a gale force wind and if both are really spinning, it's a full blown hurricane.