This process of heating the wood to above 320 degrees in a low oxygen environment makes physical and chemical changes in the wood’s cellular structure. The boards are darker in color and there is a lot of color variation- much more than a topically stained floor. It also improves the dimensional stability and reduces the response to humidity/temperature- which is great for these wide long board styles of late. Like any treatment, it varies in process by manufacturer. Some have experienced a “burnt smell” that can linger. They vary in color variation, price, and brittleness of the tongue and groove. Overall I think this process give a rich warmth to hardwood. It is a way of getting a more natural looking color and that beautiful color variation that looks like “real wood”.