You are watching actors that have worked together for a while enjoy their time with each other and with the material, and as an audience member you can’t help but get sucked into that joy. Also, the keyboardist rocks it, coming with sound cues, and improv songs that adds a layer of legitimacy to the whole thing. Every performance will be different, but there was a song in the one I saw, which was incredible.
What I didn't like
I wanted a cup of diet coke, but the audience aren’t offered anything to drink.
My overall impression
If you got time, and you want to watch something light and funny, with a few strokes of genius slipped in, this fits the bill.