Mike, I haven't crono'd it, but just guessing from the point on distance I'd guess 160ish FPS w 500gr at 25" draw which is about 55lbs, and I'd venture to guess over 180 at a 29-30" draw with 500gr. I would tend to expect the same ~170FPS at 10gpp and 28-29" that I was getting with the others. Not record breaking but more than sufficient.
Regarding the backing grain. I believe the requirements for grain are the same whether it's a board or a multiple lam bow like this. Actually multi laminate bows or even backed bows might benefit more than a board from better grain since the belly can be made of very very strong wood. Whereas marginal hickory backing might still be capable of crushing a hickory belly, marginal hickory will fail before it crushes an ipe belly. So I'd say to get the most out of it( to push the limit of the belly wood) you probably need really good grain backing. FWIW I don't think this design is pushing the limits at this weight and draw with a full 1.4-1.5" width.
So long story short, I try to use really straight clean hickory, preferable rift sawn, but I've used 1/4 and flat sawn also. Don't know if it matters. Since I've been using hickory core too I select the better lams for the back and the lesser for the core. That way I can be picky and not waste much.