I definitely have to vote for Monica Rial as Hyatt. Yes, she's quiet, but Hyatt is a quiet character, sometimes just a notch above comatose. In person, Ms. Rial is quite energetic, and not exactly quiet. She's pure energy.
As much as I enjoyed Jessica Cavello's performance as Excel, I found Larissa Wolcott to be a more than adequate replacement. The difference between their performances is not all that big.
Let's not forget Rob Mungle as Pedro.