I’ve never understood the trend over the past several years of mixing different limb woods in an America style long bow that is narrow and deep cored where the core material actually contributes a great deal to the performance of a bow. My experience with working with a variety of different woods in arrows has shown me there is a difference in the properties of different woods, sometimes a big difference, and mixing these properties in a limb of this style can’t be better than a limb made of a single wood material. Probably not nearly as important in a recurve where the glass to wood ratio is so much higher that core material is virtually irrelevant. I’d loved to see someone make a foam core America style longbow and see how it works (or doesn’t:-) Must be a cosmetic preference.
I’ve had, or now have, Hills of most of the models and find none of them are overall better than an all bamboo limb. This might be a subjective thing, I don't know.