Man, I hate when this thread slips to page two. So, doing my part, I thought I would mention that I recently went from sitka spruce arrows to ash. From a 425 grain finished arrow to a 630 grain finished arrow. Out of my Tembo, from 9.5gpp up to 14gpp. I'm sure it will take awhile to reprogram my "subconscious ballistic computer", but I have to admit that the bow is quieter and, at least out to 15 yards, or so, I haven't noticed much difference in trajectory. They also drive a bit deeper into the grass mat I use for routine practice.
I liked the spruce, but I seem to be pretty hard on them. (high casualty rate, over time) I think I will have to work at it to break one of these baseball bats! For what it's worth, it seemed like the ash shafts were tougher to get straight, initially, but they seem to be staying that way. They also seem to take a little longer to come out of paradox, but that's just a feeling; I have no scientific way to measure that. Both species of wood have the same spine and appear to fly equally well out of the same bow.
I hope someone might find these casual observations of use.