Here’s something to think about:
McDynamo is a Dynaformer son, albeit gelded. Most money ever won by a jump racer in the US. During the offseason, he is foxhunted, so his temperament must be just fine.
Most of the US jump racer trainers do foxhunt their horses in the winter. On the other hand, they aren’t breeding stallions.
Of the Roberto Sons, In Tissar, Kris S and Dynaformer have been listed as mean. I’ve heard the same about Red Ransom. Only Lear Fan is on the kind list. What about Silver Hawk? I just found a son named Robert Le Diable, which would lead to questions.