track plan layout software

I am looking for opinions on the best software available for track plan layout using a MAC computer. Thank you!

Here is one: http://www.railmodeller.de/
Otherwise, searching these forums for “CAD Mac” gives lots of results as this question has been asked quite a bit.
http://www.trains.com/TRC/CS/search/SearchResults.aspx?q=CAD%20Mac&f=&u=