My analysis of this product showed that the drill bit quality is subpar at best. I expected better durability and precision from an industrial and scientific-grade product. Unfortunately, the bits were unable to handle harder woods and the performance was inconsistent.
These are excellent Forstner bits. In a drill they cut perfectly even chips so thin that you can almost read them. I've been using large format Roman bits on my lathe for a while and am equally happy with them.
This bit set wears out significantly better than standard non-carbide Forstner bits. These bits are worth the extra cost. A note: They don't drill as straight as a typical Forstner with a more rounded outer edge. Once you get to a depth of 3/16" or use a drill press they move great.