I have done both. Got lucky that both were reimbursed by orgs (I did reforge first in my prev company).
Now reforge is great, but I could not really apply the learnings. Like basically it felt like a great YT video which is full of insights but it's not really applicable. I mean sure it works on Airbnb and Uber. But great content for sure. If you're only after content go for it.
Also, only I amongst 6 of my colleagues could finish it. I also finished it with a lot of effort. I think in that way GrowthX feels more like it's designed for you to apply. And it's not about content, it's about the overall experience feels like that. From like keeping videos on, to compulsory projects, I don't know, just way more actionable learnings.