I've been fortunate enough to attend BEA three times, but wasn't able to make it this year so participated in Armchair BEA instead. ABEA was fun and I met several new bloggers, but I wasn't able to participate as much as I would have liked.
BEA can be overwhelming, exhausting, crowded, and frustrating, but it's also the absolute BEST time I've ever had! The first day seems to be the craziest, then things settle down for the remainder of the show.
Pros - exposure to upcoming titles, meeting your fellow bloggers, networking with publishers, more totes than you'll know what to do with, and meeting awesome authors! Also, you will have no problems falling asleep at night!
Cons - your feet will be killing you no matter what shoes you wear, not enough time to do everything you want, poor wi-fi, you will hurt all over, and you'll find that impulse control can be challenging when faced with free books.
Was I jealous of all the hauls and tweets during BEA? A little bit, but that was because I had to sit it out this year and felt like I was missing all the fun. I'm a little surprised I haven't seen more BEA posts, as I've had to go searching for them. Seems like my part of the blogosphere didn't have as many people attending as in years past. Part of the reason I keep bugging Tammy over at Bo's Book Nook to post her BEA adventure in detail is so I can live vicariously through her! Ha!