In 30 years of police work I have driven almost everything offered as a "police package".
Best: '94 Caprice 9C1, naturally GM perfected the platform, then quit building it.
Worst: '83 Dodge Diplomat, OMG!
The nut that holds the wheel is the most important part. If you cannot drive, don't go out.
That said I have driven several versions of Ford's CV. The current car is the best bet for all around performance whether it be urban, suburban, or rural. Space is definately an issue. When I started in '79 we had a radio and a siren. Now days there's a radio, or two or three (seriously, how many people can you talk to at one time?) a laptop, cellphone, siren/light controller, GPS, video cam, radar/laser/death ray etc etc etc. Put your own gear in there, and you can see where a big car makes sense.
Impalas hold their own, but IMHO that is/was the worst handling car I drove in a long time. EVIL! That new Caprice looks GOOD! Anything based on a Holden platform should perform well. If it holds up all the better.
Drove a few Chargers, big motors, lil motors, whatever. Not real impressed. Goes like stink in a straight line. Wouldn't want to crash it though. NO back seat space, tiny trunk, rear visibility nil.
My personal car is an '05 Town Car, one of the few I've owned that impresses me. Snowed like heck here last year, 6 inches in Henderson alone. Coming from the midwest I can drive (i think) in the snow. I had no issues except I ticked off a Henderson cop. On my way to work, 9pm, I got off the main drag and started "playing" drifting, sliding etc etc. Copper pulls up to me, starts to lecture and recognizes me from some in service training. Says " darnit Sarge, I thought I had a live one, you still drive like a cop"