My son loves this toy. He got it as a Christmas present and it has not been off his arm since. He is totally in to Ben 10 and to enjoy this you need to be.
It's a bit fiddly to put together the first time as you'll think you will break it, but it is actually hard to do so.
There is one flaw though. Ben 10 has 10 monsters, and this comes with a disc for one included. To get the others you must buy them separately and this is not cheap. Something to consider before you buy.