With regards to the ARC Ripper end mills with the TiAlN coating specifically for 303/304 stainless I must say I am very impressed. On my SiegX2 the 14 mm (on 12mm shank) is a work horse.
However I naturally have a question which applies to other coated tooling like TiN drills and milling cutters:
What happens when you sharpen them?
I assume the coating is a micron or two thick and the resharpening will remove the coating so you are just back the basic HSS alloy?