When Platinum first came out, there were quite a few posts on Tradgang expressing dissatisfaction with the way it was holding. There were some other posts, including mine, whose experience was the opposite. My experience has continued to be good with Platinum on carbons since then. There have been times when I have shot an arrow into the brush and had the feathers rip off and the quill stay glued on.
I wish I knew what to tell people who are having trouble with it. I have been through several tubes since the stuff came out, and haven't noticed any differences from tube to tube. I don't prep the surface of the carbon shaft; I just clamp the feather and glue it on.
I have had good results using it on all types of Easton aluminum shafts too, except for the blue Jazz shafts, which are their low end shafts that I use for the classes I teach. The first time I fletched up a bunch of arrows using Platinum on the Jazz shafts, the feathers all fell off like leaves falling from the trees in the fall. My students were running around picking them up off the ground. I assume there must be some difference on the finish used on those shafts. After that, I have been sanding the Jazz shafts and wiping them with alcohol, and the feathers seem to stick okay.