I originally posted this question on Shooter's Forum, must not have been the right one 'cause it disappeared. My bad. I'll try here.
OK, you have two Longbows, identical in every way, except one has Bamboo in the limbs. What advantage, if any, would there be in arrow speed for the Bamboo-equipped Longbow? I'm considering a custom bow and need the low-down on the Bamboo speed hype I've seen. Thanks in advance for your opinions!

Someone here not tooo long ago (I think it was KennyM) built four or five bows to identical specs changing only the core (bamboo maple walnut I think) and found not much of a difference in shooting qualities between them all

Bamboo is a very light but strong material. I think the lower physical weight probably has more benefit for a glass bow.

Bamboo is very strong and very light. Its lighter than other woods and you use less of it. The lighter the bow the faster it is.

a down side is that it is more expensive than say  maple or elm. i don't know if the gains are worth the price. in kenny's test the waltun actually ended up faster (i think) good luck picking out woods.

I have never built with bamboo but I did recently acquire a HH "Big Five" longbow. It is amazingly smooth drawing for an 80# bow and has zilch for hand shock. This bow has glass over 4 lams of bamboo and is mildly reflexed.I also shoot it more accurately than any of my other bows which I am sure is more a function of the handle/arrow shelf fitting me to a tee rather than any magic properties of the bamboo core. I haven't chronographed it but it wings arrows with authority and it is without a doubt the most pleasant shooting bow I have ever had in my hands.

I like bamboo for the core.  It is light and returns to the static position a bit faster than some other woods.  The only down side, besides price is that it seems to have a bit of a tone to it when it closes.  I recently discovered black limba from my wood source and can say for sure it shoots as fast and smooth as boo with less cost and comes in dimensional stock which is a plus.