So far, we've been surprised by how well done this series is. Being a toy-selling series, we honestly were expecting the kind of shows we saw advertising toys when we were young: pointless, poorly written, and cheesy beyond belief. As adults, we actually ENJOY watching this series, and seeing what happens! Since it is geared to children (I would say about ages 8- 12), some of the plot "twists" are actually fairly obvious for an adult, but still interesting.
The ideas about devotion, loyalty, and accepting differences have also been really useful in our household, where we have been able to have effective discussions about autism, disability, and ability based on these characters and their adventures. We have also been able to discuss social interactions and ways to think about others in ways that can be hard to broach with this middle-elementary age: that people who seem to be friends may not be, that bullies have their own issues, and ideas of including others and finding your own talents when others don't include you. There are lots of other good, complex issues of relationships presented here, in terms this age group can grasp and see.
We actually find ourselves wishing there were MORE toys associated with this series, not less. And unfortunately, many of the figures are exclusively available through the larger, very expensive Lego sets (do keep in mind this series is intended to sell you toys!)