I just got used Silencers after I broke my 2.5 year old PEs. The Silencers are a lot better in bumps and groomed I find, and a bit better in pipe, But I liked my Publics better for rails, jumps, glades, powder and pretty much everything else. They pretty much were just a funner all round ski..I found the Public Enemies were more lively and had a bit more pop, and they also floated better in powder, and they were easier to maneouvre in tight trees. I had them mounted at +5 though, and my Silencers are mounted at +8 which I think is 2 or 3 cm back from true center. also the PEs were 164s and Silencers are 179s (I'm 6', about 170 lbs for reference, and ski the east coast).
The guy that said PEs are a poor man's Karma is right though, I demoed 06-07 Karmas and I LOVED them. they were a lot better than my PEs, kind of similar, but they just felt souped up compared to teh Publics.