The speakers are a benefit--I like to hear the author or representative of a product I use, because it helps me understand the product more--where is the author or company coming from? I also like to hear speakers for encouragement, new ideas, or new perspectives.
Conventions can be times to rethink and refocus, and to hone our craft. Need a new teaching strategy? Struggling with a certain subject? Conventions can be a way of getting fresh input.
And...I think it's just encouraging to see so many other homeschoolers in one place.
One time I came home from a convention with a worm. Yes, a worm! I listened to a science talk, learned that earthworms have multiple hearts...and the speaker had formaldehyde-preserved worms to give us as a parting gift, LOL! No, we didn't *have* to come home with one. Yes, my husband thought I was crazy too! I think the kids did too, but they had fun anyway.
Worms aside, onventions can be overwhelming too (sometimes there is TOO MUCH curriculum to look at, LOL!), so if you go...go with a plan in mind (and a budget!) or it would be easy to go wild & come home without gaining much.
When in doubt, I wait and buy online, and I ask myself not just "would I like this," but, "what is my plan for using this?" That plan might just be, "put it on the coffee table and see if it sparks the child's interest." There's nothing wrong with that plan, as long as I understand that's what I'm spending my money on, and if I have room in the budget for something like that.
If my plan is, "beats me!" or, "well, I hope I'll use it," then I'm very wary about purchasing that item and almost always choose to wait.
Look at the vendors and the speakers, and see if there are any that you would like to see when weighing out the pros and cons of a specific convention.
How about you? What benefits have you gained from going to a convention? Or would you rather stay home?