the smoothest bows I have built were carbon foam core. However the difference in it and yew or boo for smoothness is so little if any that I wonder if its just my imagination. Here is the problem. I feel like one is smoother and then do the draw force curves and they are the same. Sooooooooooooooooooooo. I do not like the look of foam on some bows but do on others;. I just built one that there is a thread on right now that I actually disliked the look of the foam so much that I painted the sides of the limbs black. On that bow it worked so good I may do more of them that way;
The lightest weight cores are ususally going to be the fastest if the rest of the build is the same; Core has that. Yew next and maple so close to yew its a toss; Still I have built some very fast bows with actionboo cores;

God bless you all, Steve

Bamboo sure is sweet and smooth. For the most part though I don't think there is much difference in most woods as far as performance goes though some do feel different. I think what it all comes down to is limb design not the wood in it.

Im a bamboo man also

Adding to my last reply-  i'm on the fence about carbon foam because so far the one bow with it i've shot (zipper) just had kind of a hollow/dry feeling/sounding release vs. boo/maple/yew bows I've tried.  just wasn't satisfying to me.  it drew way smooth though.  there was no such thing as stack on that bow.  pure linear.  i'm about to try another carbon/foam bow this week-  ILF riser with TT/Samick BF Extreme 'long' limbs.  Supposed to be the top of the line ILF limbs other than Border hex.  I will share what I find out.  If it has that same 'dry,hollow' feeling/sounding release i may have to sell it also.  i'm a sucker for the whole shooting experience, draw, release, arrow hit...don't just care about fps.

concerning maple, my 66" leon stewart t/d slammer has select maple cores and it is one of the sweetest shooting bows i have ever had the pleasure of and flat out smokes an arrow, its my favorite bow.  my miller old tom w/ tempered bamboo is tied with it.  what a sweet drawing bow that has a lovely soft thump for a hill bow.

nineworlds9 I'll be watch for your post.

Carbon/Foam, then everything else.

Brushwolf-
will definitely share what happens with the TT BF's and the two different risers I picked up (1 Hoyt Excel, 1 Morrison metal)

+++I realized that a differentiation should be discussed perhaps-  

REAL boo vs. actionboo

Real boo, heat tempered or however, without question is a smooth drawing material and an old standard.  it was HHill's material of choice.  'actionboo' on the other hand is a product made FROM bamboo...it is basically laminated bamboo/ bamboo 'plywood'.  Real boo seems to be popular with the Hill style bows like my Old Tom, but a few boywers of R/D style bows use it as well, one I used to own was a River Raisin with real boo lams.  Fast and VERY quiet bow.  Super smooth, you could just draw and draw that thing.  I'm no expert, but please somebody chime in who knows some more and discuss how the boo vs. actionboo plays into 'wolf's original query...

Definitely prefer bamboo or maple.  Bamboo feels more consistent to me, maple is right there also.

Tried the foam, just couldn't see it being cost effective for how I shot with what it gained me.  It was more stable in extreme temps though.

Carbon/glass is a whole different ball game over core materials.  In that case carbon.