How to tell which academic enrichment opportunities are worth it?

When asking if they are “worth it” I wasn’t focused on worth in terms of increasing college admissions likelihood, but rather “worth” it in terms of whether it would be a valuable experience overall. A lot of these places can put together some great marketing materials but in the end it comes down to whether participants feel like they got something valuable out of participating - that’s what I’m trying to figure out how to evaluate. I guess maybe I could ask our GC if other students from our HS have attended any of these in the past and what they thought about them.