Is a fixed wing more efficient in reaching a certain altitude than rotary wing?
A helicopter in forward flight is more efficient than a helicopter in vertical hover, due to less induced drag (and more form drag which becomes a problem at high fwd speed).

Fixed wing aircraft are more efficient than forward flying helicopters because:


The rotor flow in forward flight causes fearsomely complex aerodynamic interactions in flow with the fuselage and other components, which causes a particular type of drag that a fixed wing simply does not have.
When the helicopter is in forward flight, the rotor disk has the same characteristics as a fixed wing: less induced drag, higher form drag. But it will be a circular wing, which is always less efficient than a beautiful slender fixed wing. The slenderer (is that a word?) the better.