I cant speak for the main speakers but unless you build your own SVS is hands down the best sub for the money with HSU coming in a close second I highly doupt the EMP sub is anywhere close to the quality of the SVS.
There was a day that I would have said not really but today movies really use the surround channels to the fullest and I would not ever go back to just two speakers particularly movies like the Dark Night.Is surround sound going to make that the movie that much more enjoyable?