Personally, I think it all depends on the type of projects you are tackling. ?It is true that the nickers will yield better cross-grain joints, and tend to limit chip-out, particularly with the top veneers on plywood with hardwood faces, and with melemine particle board. ?The Felder dado cutters also produce a true flat bottom. ?But if you’re planning to do things like make Green & Green or Scandinavian bridle joints, like the one shown below, you either hate them or find them enhancing the overall “craftiness” of the joint. ?

The nickers on the Felder unit are carbide, and thus challenging to “hone down” - I did it once for a project and don’t recommend it. ?I have a pair of Forrest Dado King 12” sets that I had bored to 30mm and the pin holes installed which when sharp deal with cross-grain chip-out as any ATB style saw blade. ?I don’t use them often, but they have served me well, especially when cutting very deep tenons on the shaper for projects like Post & Rail fences. ?See below: