The Impala's in general are fairly reliable, that is a plus for a GM product. You have a choice of 2 V6's and of course the V8. As this is a front wheel drive car, the V8 has a lot of torque steer. It is also pretty front heavy, so it is not a handler. They are roomy enough, and competent enough, but still do not compare well to the best in their segments.
-V8 (good in a straight line)
-improved interior quality
-depreciation is steep
-V6's old school
-typically rate low/mid pack on most comparisons
-not really handlers, don't feel very sporty
-ride never really feels settled
-still not as good as Honda/Toyota/VW
RUN AWAY AS FAST AS YOU CAN. That cylinder de-activation was a horror story for them in the past and I wouldn't touch it until it was proven in the long run. Besides they don't save all that much, larger motors with overdrive generally are at their best on freeways anyways when it comes to fuel mileage. They need the help in city traffic and this motor only does it's cutting out on freeway. Ask yourself this, how well have GM motors done this past decade, would you want a radical design like that motor built by them? NOT
I have a 06 ss and I think its the best sports sedan you can get for the money. The only thing I can say bad about it is the mpg is less than they say it is I have been 19 mpg combined and most of that is highway.It rides and handles good. The car is a way better value than the three mentioned. They are over rated.