All that matters Nonpareil1710 is that the program you use does exactly what you want it to do and will need it to do now and in the near future. You can use many different 3d modeling programs, so you can also use it to create many 3d models in general, of course that is if you will create anything besides just terrain in the near future which people do. You can use a program speifically for terrain it may come with certain tool, which these tools are just shortcuts that allow you work faster. Just because it has tools speific toward terrain editing doesn't necessarily mean it better. Since in the end it all comes down to what I said it depends on what you will need

So think about what you will want to do with it, also what you will need to use for it now. Then go and find the application that offers you exactly what you want.