Rog,
I actually used the ADF in Fat Albert flying IFR a week ago... A line
of nasty stuff was blowing off Lake Erie right at Port Clinton and the
area was IMC... I wanted to air file direct from Toledo, Oh to Akron,
Oh and the Akron VOR reception was unreliable (temperature inversion)
at that time... I was filed as /A... The enroute controller inquired
if I had enroute IFR GPS... I replied negative, but I did have an
ADF... Bang, I was cleared "TOL (vor) direct AK (ndb)"... So, score
one for the old technology... That said the moving map GPS rode shotgun
for the ADF receiver until we were back to VMC..
The biggest problem with ADF reception anymore is the lousy programming
available on the AM stations...

denny