I'd go with the Dyad based on
Peter Jon White's experience. He prefers it over the Mavics and says the Dyad is "virtually impossible to crack".
I've heard the 719 is good though. In my experience Mavic makes some great rims and some with tendencies toward cracking at the eyelets. I've beat the daylights out of some low spoke count Mavic road racing wheels and they truly amazed me. On the other hand I've had one set of Mavics used for mountain biking and one set for touring crack.