For what it's worth, I actually did the series with my kid and have learned quite a bit. It's shifted the way I look at and approach building lego. I'm quite confident in my ability to build nice MOCs on the fly. I have a few ideas that I'm sorting through, to possibly refine and submit one of, to Lego Ideas. And maybe my idea ends up being great or maybe it ends up being crap, the point is that it's not something I would have attempted to accomplish before doing the MBAs. To me anyhow, I, by far, learned more from these sets than any large build.
To each their own.