Gone every year so far. Company has sent the entire dev team (7 this past year). We're less than a two hour drive away. It was an easy sell for us because of cost. Tickets, hotel, travel, and food (the catered breakfasts, lunches, snacks, and pig roast are awesome) costs less to send 7 (8 or nine will go next year) than to send 2 developers anywhere else. Some talks are great, others are ok. Its great for netwotking and getting exposed to things outside your dev stack and for us its a team building function. You get out of it what you make it. They are trying to incorporate more family and kid stuff. Our team includes single devs, married devs, and devs with kids (though no families came with this year and would be a non company paid expense). It's also something simple our company does to stand out from others in the area (helps retain and show respect and care for developers from the company) feel free to ask me if you have any questions.
Add: There are some well known people from various dev communities that attend and/or present. Its kindof cool to be feet from them or even better getting hang out with them since its not massive in head count.