I have done the H400 and the Multiple Star Observing Program (MSOP).
Most of the AL programs come with a bit of challenge. I would say, they get you out to see something you might not have gone after.
I think you learn something about what you like and don't like about the hobby. You learn about your equipment and where it might fall short for the objects you are targeting. You do learn about the nature of the things you are looking at even if it is from the repetition.
H400 has quite a bit of repetition. The MSOP has plenty of that as well.
I liked the MSOP. There are quite a few challenges in there. I did get quite used to breaking down which points of light were members and which ones were optical interlopers. It was a little frustrating at first until you can wrap your head around what you are looking at.
I typically have several programs in process. I do some back and forth if I am not feeling a certain desire to figure one thing I can look at something else.
I have four on the burner right now: the H2, PN, Solar Neighborhood, and Two in the View.
It's kind of odd, but one of the funnest programs for me was the Asterism OP. Once you have seen Davis' Dog you can't stop returning again and again!
Have fun!
Jeff