I'm currently evaluating the Edius 5.
I can tell you so far that I'm very enthousiastic; this Grass Valley software is really fast and efficient.
I find specially that if you work with a lot of sequences, you have live view on the number of monitors you want and the mix is just real time.
I was very impressed by the efficiency of the workflow.
This is a first impression that does not replace extensive use, so I'll post more later when I got more field experience with this software.
In short, if you have a lot of volume and need a very efficient workflow, you should get the trial version and test by yourself.
Edit: Coming from premiere interface, it is very easy to adapt yourself to Edius.