YES, you are comparing very different vehicles. Although, some that like the Murano, may like the FX or the EX, and vise versa. They are all mid size cross over SUV's, obviously the EX being smaller. I know my wife always says she thinks the FX is for men, and she would look goofy driving it, that was one of the reasons we bought the '09 Murano. There is some more information on the following thread:
zerothread/312931
I also did a mini comparison vs: the Acura MDX, which in my opinion, is a true competitor to the Murano, along with the Lexus RX, and the Toyota Highlander. Check it out!