We have quite a collection!! We got it for my boys 4 & 6 birthdays last year. My oldest is a builder and this is right up his alley. He builds and takes apart and then starts all over again. He has quite a difficult time entertaining himself, but this is the one toy that has had more ways to play with it that he is still playing with it a year later. My 4 yr old is not a builder, but he is the one that like to play with the RC's. It is quite expensive, but worth it b/c of the different types of play that they can do with it. It works for both imaginative/dramatic play and critical thinking/building. All my 6 yr old asked for from Santa was Rokenbok.
The company is great!! One of our RC's didn't work and they sent us out a new one. We think it is one of the best designed and expansive toy for boys(and their dads) One of the things we did was buy a lot of all different extras on ebay. This allowed him to build so many more structures. It does take up a lot of room. I bought a drawer organizer to put his different pieces in and it still needs to other bins to put structures and vehicles in. I hope you guys enjoy it...we do!!