I've gone - as a librarian, not as a writer - for the last three years. The best thing we did (my sister and fellow librarian got me into this) was the booksellers' speed dating luncheon and the author tea. It's got to be exhausting for the authors, but we met Jesse Andrews and Kevin Henkes, among others, and Kevin Henkes showed us the ENITRE PROCESS of creating and revising one of his picture books. It was beyond awesome!

And, both this year and last, we learned about books that the kids in our libraries would love. And we got lots of free copies.
I was feeling sad that I couldn't go to Chicago, but we'd have to do it on our own time and money, and I don't see that happening. If anyone is in the Chicago area, I really would advise it.
One thing: If you have a blog, peoples' eyes light up. I've really got to redo my business cards to emphasize that I'm a blogger as well as a writer and librarian. So - if you go, and you blog at all, be sure to let people know! Whether there will be as many ARCS I don't know, but I know publishers and authors are always looking for book reviews!