Whilst there are some great impressions (and a few terrible ones too) in this the laughs are hit and miss. The worst of the show is, as I stated in the review title, the pretence that this show is done off the cuff. There is a musical round which highlights this in particular where people are doing perfect duets with each other and a guy in the band who would have no idea what the comedian would be doing. There are also rounds where people are reading from prompt cards. If this was just people delivering their own jokes off the cuff it would likely give more laughs than it does in it's current format.
This has a great deal of potential but in it's current state it is destined for just a single series before being axed.