I own a fully serrated SS Police. I chose the fully serrated version since I have enough plain edged knives.
In addition, I love the look of full serrations on the sleek Police. They just seem to go together. It looks like a barracuda with an attitude problem!
If this is your one knife or main knife, I'd go plain edged since they are more versatile and is easier to maintain and sharpen.
If you do a lot of cutting of fibrous material, or like the cosmetic look of serrations on a Police, as I do, go fully serrated. In addition, if you aren't keen about sharpening your knives, at least a serrated knife will still cut (or at least saw) to an extent even after the edge has dulled.
As for the argument for or against plain/serrated blades for combat. Realistically, most of us are more prone to be cutting bagels with our knives than going on a Rambo rampage. Not to mention that either type of blade are sharp as a bastid out of the box. Hey, I don't care whether you have a sharp plain edged, or serrated edged if I piss you off and you happen to be holding a Spyderco Police. Either of 'em would scare me!
That's the one of the turn-ons of the Police. It's shiny stainless steel handle, the weird scalene triangle shaped blade, and utilitarian looks gives it a bullying, intimidating look that's akin to a straight edged razor.