Fun and a reasonable price for a Lego product...as in only costs your fingers and toes and not a whole arm and leg.
My son loves Lego trains but the cost for most of them is far above our price-point. These small trains are fun and still rather affordable, so they have been the product of our choice for a while.
Unfortunately, they are very small and still rather expensive compared to many other toy brands and if you loose a piece, be prepared to spend almost as much as the train to replace the one part.