Original Message

Taking a look at the cruise performance curves in most helicopters, 4-7 thousand feet is most efficient.  

Airplanes are machines which experience those issues, as well.  However, swap tail rotor for rudder.  

Most low flyer accidents tend to be the result of CFIT or LOC.  I also don't know of any IFR operations, with the exception of takeoff and landing, which are below 1000'.  Most are well above that altitude.

Who gets into helicopters to fly that high???  I and most of my professional colleagues do...