This is one of my four year old's favorite shows. I like it too. He loves super heroes, and I like the idea of the "super readers" to the rescue. The songs are cute, the pattern is repetitive (which my 18 mo old loves), the graphics are great, and I love the message.
The team works together, looks to books for answers, finds letters, spells them out, interacts with the viewer, and then applies the lesson learned to an everyday situation.
Some critics have commented that the fairy tales are changed, and isn't this a rather anthropomorphic view of the world? I disagree. I think it's fine to send the message that you can get what you want out of a story, and that if you want, you can change the endings. After all, I encourage my kids to pretend stories and change the endings when they don't work the way they want them to.
Overall, an excellent show. I'm not a big fan of commercialization, but I would really like to see some related products released. My kids would love to play with Super Readers and their flying machines!