I have cracked the front base plate by accidently poking it with my ski pole in some really cold weather in switzerland last spring. I was trying to release the binding toe, missed, and jabbed the plate. It cracked and the crack shot down under the plate. Fortunately there is a chunk of metal reinforcement in there, but I could not lock out the front of the binding, in the middle of a berner oberland tour on some big peak. Darn!
The next event was cracking the piece around the crampon attachment. This was again in cold conditions, and happened when I was twisting down trying to get the crampon on while on the move. Fortunately, these were the newer comforts (replacing the cracked ones above) so they had the metal reinforcement for the crampon holders. The previous comfort model has plastic crampon holders (yikes). Wouldn't it be fun if that broke sometime while cramponing?
The fact that I'm still using dynafits despite these issues I think says something about their performance. I certainly ski differently in them than in Fritschis though. Not so much the actual skiing, but taking care when putting them on and off, changing to touring/skiing mode, etc.
I've never had issues getting them on in deep powder, or any issues with icing. I also like how they are easier to fit to a pack. I still have my old freerides on some bro models when I want to "unleash the hounds", as it where.