I watch it ALL the time!
It all began one day when my nieces were glued to Treehouse...
... They wanted to change the channel when it came on, as apparently, they found it uninteresting... I, on the other hand, found it to be the most intriguing thing!!
You are sooo right when you say the humour is smart and witty. I love that it seems so unscripted and real.
... Do you ever wonder why sometimes you see strings, and other times you dont? (Small) or who could possible fit into Big? (i'm convinced it's a costume that someone wears; look at the finger movements!!)