The Pros are definitely more blade assertive. Especially when they are new. It could be that they are ground to a very thin edge (ala their DEs). The Pinks would have the coatings to smooth out their edge.I looked at the Kai website a while back.... At the moment, on said website, they only list two blades: the Protouch guarded blades and the "Pink" unguarded blades.
It's funny... I just did a repeat test I did two years ago now, when I got my first razor that happened to be an AC razor. I used all the AC blades in my La Faulx SS, other than the Feather ProSuper I forgot to bring along on the 3 week trip to Bali.... I've been using the Kai Protouch pretty much exclusively for the past 2 years, but I wanted to see if I'd learned anything or if my preferences had changed... At the end of the 3 weeks, I ended up ordering a couple of the boxes of ten packages of the "Pink" unguarded blades, as I liked them a bit more than the Protouch....
I noticed, I didn't like the Feathers as much as I remembered, the exact opposite of @bebo8 . I have quite a few Feather ProGuard packages... but I only had two of the Kai Pinks... I still have quite a few Kai Protouch guarded blade packages and like them a lot as well. I didn't seem to like the Feather Professionals.. I got a couple of cuts on my upper lip: one each on two shaves.. none on the third, but no cuts or weepers with either of the Kai blades. It could have just been coincidence... but it was odd. I had never cut myself with either the bronze La Faulx Classic or the SS La Faulx Classic in several dozen shaves.