I would consider calves an exception to the rule. For the most part, any HIT program does not usually include more than 2 sets per exercise, and 3 sets is definitely the extreme. For calves, I suggest going against the HIT philosophy. I only go against the HIT philosophy because of the unique properties of this muscle. When you use this program, do not rest longer than 30 seconds between each set. The calves usually respond better to a high rep, high set, low rest-type program. This is a very stubborn, tight muscle group so make sure you use that 30 second rest to stretch your calves and loosen them up. I actually suggest that you use this higher set program:
The calf is made of two parts, the gastrocnemius and the soleus. The gastrocnemius is definitely the much bigger, stronger, and most noticeable of the two muscle heads. The standing calf press is the most direct exercise you will use for your gastrocnemius. Although you isolate your soleus more on the seated calf press, I don't feel that this is necessary. The standing calf press definitely hits your general calf structure much better than the seated calf press.