http://www.pprune.org/forums/showthread.php?t=227983
This thread discusses that issue quite well! However, there is no harm in starting another thread.
If I get lost, I can slow down and look out the window and map the land features to the chart! IFR - I Fly Roads, rivers and railways! A typical altitude for a light helicopter would be 2,000 feet and an airspeed of 70 knots!
Most small helicopters do have a reasonable amount of rear visibilty and a lot of peripheral visibilty. However, I cannot compare as I have never flown fixed wing.
Cheers
Whirls