This thread is crazy old, but I thought I would give my input in case someone comes along researching Liza. So here goes:
I entered Pitch Madness in March, and Liza won the full manuscript request. She read my book in one day, offered rep the next. I had other agent requests for the contest, so I told her I would give her an answer in two weeks, then nudged the other agents. But I knew before the two weeks were up that I wanted to work with Liza - her enthusiasm and love for my book were unrivaled - so I signed with her.
Liza is smart and savvy, and she works fast. My book went from first read to sold in something like six weeks, and will release next spring.
About the exclusives: Liza hires paid readers. Not interns who read and report for her, but paid advisers - former editors, etc. It's a decent expense for her, so she asks for exclusives for a bit of security. It's not ideal for the author, I know, but there's a reason behind it.