The common misconception is that products made with MDF are lower quality and using all solid hardwood is superior. There is a lof of debate, but we have found that using sheets of high quality MDF core with a hardwood veneer produces a much more stable product and standard hardwoods are much more susceptible to warping with enviromental changes, such as humidity. We ship doors all over the country and simply cannot control these enviromental changes. For this and other reasons, we find using a high quality MDF core provides a more consistent and stable product.
For more information on MDF, please see some of the following articles we have found contain great information and explanations.