Depends on the individual piece of wood. Generally speaking, yes straight grain wood is a bit better. Birds eye is considered defect. It's not a lot different than burl. The more & larger eyes in a piece, the weaker it will be. But on the same token, birds eye grows on very slow growing trees. Whether the defect causes the tree to grow show, or the slow growth causes the defect is a mystery. But the heavy, tight grain gives a lot of birds eye a density & strength that healthy maples don't get. It's kinda like "retard strength" for lack of better terminology. It's just freakishly harder & stronger when it's clearly defected. So even though it shouldn't be better because it's defected, a lot of it is far superior to straight grain. Personally, I have noted that the smaller eyes make the strongest, heaviest & best toned wood. The large eyes with deep wrinkles & swirls make the weakest & dullest wood, though it looks best. Hope this all helps.