Congratulations to Spinwing and Otter!
Some sensible, reasonable and well researched debate has led to an outcome that even bystanders, such as myself, can learn from.
I hope some other Ppruner's can follow your example in future and help keep this forum worth reading, i.e, without reverting to a slanging match when one has a differing opinion and one is able to graciously accept being corrected in the end.
Good work gentlemen.