taper- my opinion is that it is very much individual. hard thing for many with taper is that the mind is use to the constant rigors and routine of training, that when less time is spent with the activity during taper athlete struggles.
marathon is not something to go into with accumulated fatigue though. taper plays into natural part of training of unloading.
i would agree with low mileage no benefit.
i can relate this on marathon taper that my wife did this fall for first marathon (i'm a little off, log book is at home)-
4 weeks out- 84 miles- equaled high of buildup (ran 20k race)
3 weeks out- 68 miles (included 14 miles at goal pace)
2 weeks out- 55 miles
1 week out- 40-45 miles
week of- 45 miles (includes 26 of marathon plus 1 mile w..)
she struggled from 3 weeks out to abot 5 days before with legs feeling very sluggish and just not being able to run paces that were a piece of cake before. 4 days out she felt like a million bucks. from talking to others this is normal.
then at the race, pace that seemed so difficult two weeks out, she started out first half of race slightly faster than, b/c she just felt so good.