The other site that some referenced makes a point of saying their wood doesn't have bark. Is that a big deal?
I have heard arguments on both sides of the isle on this. Like Kona, I think how thick the bark is makes a difference. Most fruitwood trees tend to have thinner bark
For pellets, I have used BBQer's Delight which advertises "No bark," and I have used Lumberjack which proudly uses bark, claiming 90% of the wood fiber flavor is in the outer layers, which includes the bark. I have used both with good results.
For chunks, like Kona, I will leave at least some bark on, depending on how much bark a type of wood has. Many fruit woods tend to have thinner bark than some other woods.