tomica world and takara... whats the difference?

Technically its illogical to compare the two. Takara is just a company which merged with Tomy in 2006 to become Takara Tomy after Takara went bankrupt. Similar to what Geris pretty much said, the Plarail range in the 90's pretty much was a larger version of what the Tomica World range was in the late 90's, with the exception of European trains and it would have been the same with the Tomica range from 2010-2013.