Cranfield's information was recently presented at a cabin safety conference...having read through the data, I must admit that I'm sceptical. The difference in evacuation times is not particularly great (4.5 seconds for the first 30 people). In fact, in at least one of the trials the 36-inch pitch evac time was three seconds faster than the average 29-inch pitch evac time.
Although the time difference between the seat-pitches tested is considered "statistically significant", that's just a mathematical definition. Given a real-life crisis and the various factors which such a crisis would throw up, I can't see that anyone would seriously believe that narrowing the seat pitch would help anyone.