SPIFR is an absolute doddle - with say a nice modern Garmin/STEC setup, all working and up to date. But when its not and you lose an engine or a vac pump and the weather goes to poo - then it gets bloody dangerous and one cannot help wishing at least Bloggs was along!
Trouble is most of those 30 year old 20,000 hr hacks we fly just don't have that gear - and half of what they do have is often U/S.
In theory SPIFR is fine - in practice?