It's a train, it's a stacker, no it's both! Yes, it has many pieces that 2 year olds don't necessarily clean up very well, but it provides my son with enjoyment almost every day. So how can I complain?
I purchased this for my niece's 2nd birthday. She loved it! The pieces are easy for toddlers to handle and she didn't get bored. My two sons (ages 18 months and 5 years) enjoyed playing with it as well.
My son received this as a going away gift from our landlord in Germany. He's had it for a year and a half and can still play with it for hours. While he was too young to put it together when he received it (he was 4 at the time), he was old enough to handle it with care and enjoy it. It's amazing to watch him play and imagine. He loved it so much that Santa brought him the airport and control tower the following Christmas!