I’ve worn Adrenalines for about four years. I got a pair of 15s back at the end of March and the store gave me the same warning and suggested I move up a half size. I did that and the shoe felt too big. So then I got my regular size and the toe box felt too tight. So then I went back and tried a parade of different shoes. This particular store is excellent when it comes to allowing returns when a shoe doesn’t work. After several fails with different shoes another employee suggested we go back to the GTS 15 a half size up (as first suggested). This time I laced them up all the way (in the past I hadn’t used that last loop). This solved the slippage problem and the toe felt great. I was off and running. I put about 500 miles on those and I am on my second pair of 15s now.
Hopefully when the next year’s model comes out in November any adjustments will be communicated ahead of time. I hate having to navigate through the tweaks these companies make in their designs.