Let us know!!
Not attending but if I was, I would pick something complicated where I would likely learn something. Say garnishments (in the broad sense of the word) or benefits. I know a lot about benefits, but there is always more to learn. I would not attend discussions I already know cold. I remember attending a CA labor law seminar a long time ago, and half the stuff they told us was just plain wrong. Be careful with seminars that cover too much ground in too little time. And look for handouts. If the presentation was any good, it beats taking notes.
Change of topics, but a lot of law firms have free webinars you can sign up for. They tend to be run by people who actually know what they are talking about and are often timely. You usually get a nice PDF of the presentation.
Here are some good answers from the Symmetry team: http://www.symmetry.com/resources/payroll-news/2017/04/24/what-symmetry-software-is-most-excited-for-at-apa-congress