No NDB approach is "hard" Dangerous is a different matter. As an example of CAA's slow action take a look at what happened up in WR. The approach use to be a single NDB approach flown past Marsden point down the harbor, how many years did it take before CAA realised that the WR NDB was so prone to inaccuracies that they finally put in a second NDB "SF" and made it a twin NDB approach.
MOR the guys flying the Beech's wont get EGPWS's because they are also GPS equipped, we are talking good old raw data ADFs.
I have just been out for dinner with another colleague ex Eagle and discussed the approach with him and he said the same thing as I have already posted, A false turn on of 5-10 Degrees on a 12 mile arc equate to an error of up to 2 miles which would start putting you pretty close to certain hills.
Anyway im only speaking from doing that particular approach on average 4 times a week for 4 years not approaches in Innsbruck.