Joanna is an awesome lady and a great agent from what I hear. I queried her a while ago and she had requested a full. Within that time, I got an offer from another agent and let her know about it. She said she had too much client work to do to get to my manuscript within my time frame, so even though she hated to, she'd have to step away and not counter. She's really personable and nice and I hear she even rejects with style.
Her and I still keep up correspondence through email. How many agents who aren't yours can you say that about? If I wasn't with the agent I am now, I know she would be the one I'd want.