My experience with Kennametal has always been that they have the very best turning inserts in the world. They are still working on milling.
Sandvik, to me has the best milling cutters out there right now. They are very expensive.
A better solution is to go with Iscar. A bit cheaper, and very well made. They have a high feed mill out right now that is just blowing everything else away.
https://www.iscar.com/eCatalog/Famil...pp=65&GFSTYP=M