My DS9 is signed up to go for this third time this summer. He went the past two years (this year he'll be in the 4th-6th group). They mix small groups of variable ages -- so you don't just have a team of third graders. Our first time was in another school district that had a lot of experience and a massive total group. He enjoyed it, but he did complain at first that the inventions weren't real -- but he embraced the prototype idea after that. He struggled a bit with the group being very loud when all together (same as during school). He also is a collector of all his creations, so I was impressed that he was okay with how his small group determined who got to take home which creations at the end.
Last year, it was offered at our local school, and new to our district. Definitely had a few kinks to work out, but the smaller size group was much better, far less chaotic.
DS has watched the demo videos about this year's modules and is already thinking about what's to come, and we're collecting random bits of reusable and recyclables in anticipation (things like worn out girls tights are oddly helpful when making inventions that move mechanically). He loves making things.
DD7 tried it last year (when rising to grade 1) and did not want to go again this summer. She said she did not like being directed, and wanted more time to create freely, as well as more help with the tools (loosening things) in the take-apart challenge.
For the price, for the amount of time they spend together, I think it's been worth it, but it sounds like it depends on the school. DS now has the opportunity to take some GT stuff, but the bulk of it happens during the same week we signed up for CI, or when we're traveling, which I didn't realize when we signed up. But those GT classes are twice as expensive anyway, so maybe next year. :-)
