I just bought an 09 LTZ with the 3.6 and it compares similary to the LT I rented with the 2.4. This is really a subjective thing but I find the Malibu the most well balanced compromise of comfort and road handling car that I've driven. I'm coming from a choppy riding Mazda Speed3 so this is a big increase in smoothness and quietness. I feel it's pretty well composed on rough road surfaces too.