NavList:

Mark,

No map or chart is best for all uses.  That being said, the Mercator is not good for many, modern, applacations. IMO

Any map is OK for small area - you would not notice a difference ( not talking about artic - another whole ball of wax ) but large area is where the differences show.  You say you like radar.  You cannot plot a radar bearing on a Mercator chart.  Any bearing from an electronic device ie. RDF, or VOR ( an aircraft navaid ) can't be plotted because they are great circle.  Even a visual sight is great circle but is short distance so any projection will do.

I have flown over 50 years and in all that time never used a Mercator chart.  All aircraft charts ( that I used ) were Lambert Conformal Conic, both Air Force and civilian.  The military TPC charts are 1 : 500,000 and the larger ONCs are 1 : 1,000,000  The civilian Low Altitude Enroute by Jeppesen are also Lambert.  ( Looking at my old charts I see I did use a Mercator once but it was a Transver Mercator between New Zeeland and Antarticia )

Because airplanes fly high our visual range is much greater and because most navigation is done using electronic aids the need to plot a bearing onto the chart was needed.  Early on ( early 20th C. ) pilots used marine charts but very rapidly developed avation charts - most in the Lambert Conformal Conic projection.

Just my view from the pilot's seat.

John H