[ManicMechanic]

I'm not familiar with the Vex IQ kit, so I can't comment there. However, having coached both FLL and a Vex HS team, there there are some program considerations which could be important. Fundamentally, what demographic/population do you serve, and how much/what kind of involvement do they want?

1. The FLL Project is a big draw for teams with mentors and students with no previous background in robotics or programming. There are teams with a poorly functioning robot who win project or core values awards who are willing to stick around for multiple years (and get better at the robotics) because they have an opportunity to succeed in some way. Without that opportunity, they might be tempted to give up.

2. FLL season is typically 3-6 months (Sept. - Nov. and beyond, depending on whether you advance). Some teams benefit from an off-season and get burned out if they compete year-round. While theoretically, you can take an off-season any time with Vex, you feel that you're getting behind other teams that work year-round if you do. When I coached FLL, we typically spent the spring non-competitive season meeting, building, and programming fun projects of the students' own choosing and working on previous years' challenges. The students reported that those times were some of the best times for our team-- a reward, after a season of hard work. We did something similar with Vex, taking an off-year, and a student reported, "I feel happy when I'm in this room", which would have been less true in the throes of competition.

An important consideration is age. There's a tricky trade-off between pushing too much too soon and not pushing enough.

If you want to start students on a path that ends with more intensive/hands-on involvement in higher level robotics, the Vex program is probably the way to go. But if you want to expose and involve a large number of students to STEM who use robotics and/or programming in a more peripheral way, I would go with FLL. Some of my FLL/Vex alumni (college students & grads) have designed products for people with special needs, because they became deeply immersed in the special needs community. They wouldn't have had time to "crossover" to that community if they had focused on performing at the highest levels of Vex. One student even remembered FLL's "No Limits" theme (designing for people with disabilities) and built an engineering project specifically with Universal Design in mind.