We've had this one for several years (two decks actually) having bought it at Origins, about 2008. There's more game there then one might think, especially when it gets competitive. We have played it with from 4-6 people (using two decks for the 5-6 player games and have always kind of enjoyed it. Its not going to ever make my top 20 games certainly, but given a choice between Cabo and Uno, Cabo will win out everytime.
I don´t like the comparison with UNO. This game is more on par with Hanabi and is so much better than Hanabi. With the recent spiel des jahres winners I could easily imagine this one as a nominee for the award.
Other than the action cards, I played this game thirty years ago with a regular deck of cards. Sorry boys but this really shouldn't have made it to Dice Tower. First time I'm going to say this: Epic Waste of Time.