Can confirm new 6800 pedals are tragically, hilariously stiff when new.
Can confirm also the potential for tibiofibular hypomobility resulting from excessive high-tension unclipping, which is awful awful awful.
Recommend counterstrain after using new pedals. Also breaking in with older cleats.
Not sure why these even have a tension adjustment. They go from "good God, are you kidding" all the way up to "officer, he was so frustrated he threw his bike on the tracks, and the impact of the train destroyed everything save these pedals, still clipped to his shoes" tension.