I think the concept itself had potential, they just didn't utilize it to the best potential... I like the idea of us seeing just what happens on these trips Buster has with his dad, and learning about different places and the people there, what they do, etc... however, I think PFB ended up turning into another tired PBS Kids gimmick of having live-action kids intertwined on the show... I'm sure they were looking to cut costs for production.
I also didn't really care for the redesign for Buster's dad... you know, prior to PFB, anytime we got any kind of glimpse of his dad, be it in a photo, or briefly in a flashback, he pretty much looked like an adult version of Buster... but here, he looks like a creepy albino man with bunny ears protruding out the top of his head.
It was also a little odd trying to adjust to Buster carrying on the show himself, after all those years of being used to Arthur being the star, and Buster being his second banana.