i have been to a few..i consider most of the seminars lame and rarely go to one..if you like socializing with some of the hottest ladies in the business..you can't go wrong attending..

Besides Exxxotica & AVN, are there other similar shows?

I seem to remember a show that had past Playboy Bunnies, Penthouse Pets, adult starts etc. signing autographs. It was very similar to Exxxotica.

I've been to a bunch of shows.

At Exxxotica (and most of these events) you get to meet the actors and actresses up close and almost personal. You can chat with them, get their autographs, buy pictures, dvds, etc.  At Exxxotica, there are also "stage" events like quiz shows, performances (Stoya one year did some phenomenal acrobatics) and more.  There are also "after parties" that take place after the show itself closes.  The seminars, as someone pointed out, are not only lame, they are nearly impossible to enjoy because of the too loud music and the lack of walls that make it impossible to hear whoever is speaking.

There used to be a show called SuperMegaShow in the NY/NJ area that had mainstream actors/actresses as well as Penthouse Pets and Playboy bunnies.  They found it "unprofitable" to continue in the area and now only have shows in Boston once a year.  But you can still see lots of adult models and actors/actresses at the shows.

There have also been a few other shows around the country with similar content but few, if any of them, have survived except for Exxxotica and AVN.  

To be honest, except for the ability to meet them in person (and maybe if you're lucky get a hug or a kiss on the cheek) you're better off staying at home and joining sites like streamate (or similar chat sites like myfreecams or chaturbate) or join their web sites where you can chat with the ladies online.  You can still get signed autographs from them through their websites or chat rooms.  But it's a lot less noisy, less crowded, and you don't even have to have clothes on.

My $.02.

Glamourcon was the event that had many Playboy and internet models.  They used to run 2-3x a year in LA and one show in Chicago.