One of the things we liked about tickets was the e-mail sender in the box on the left, and technician notes on the box to the right. We really don't like having to swap notes between internal and external, its an extra click and now you can't see your notes and the e-mail to the customer at the same time.
I found a setting to have the default status of the comment to be internal. That way you have to decide and take action to send it to the client. /settings/tickets -> advanced then tick the box "Ticket Comments - default to Internal instead of External"
... and you KNOW private comments not meant for the customer are going to end up going out to the customer by accident... major major issues ahead with current proposal for new UI