How do I know what the right train set is to get 3 year old nephew, thomas or the geotrax trains?

Thomas the tank or geotrax? My wife's uncle has a three year old boy, and his birthday is coming up fast. I'm wonderin which type of train set makes the most sense to get for him, either the thomas the tank engine set or the geotrax train set? How do I know what the right train set is to get him? thanks!

You might try asking which train set your nephew would be more interested in or see if they have already started collecting thomas or geotrax trains.