We also tend to like the M56 better than the M37, as the V-8 powertrain feels smooth and strong; the M37's V-6 is one of the more raucous, vibration-prone engines in the luxury-car class today, at least as felt from the cabin. Excellent handling, nicely weighted steering, and a firm but still comfortable suspension make this big sedan agreeable in most respects.
There's real backseat space, too, and even those who worship German luxury will like the change of pace in this curvy, wood-and-leather-trimmed cabin. The only issue is that the M56 is still a bit of a wild card for status-seekers; while we hold it in high regard, and its price might be the same as that sedan with the three-pointed star, the respect it commands in public probably won't be on the same level.
Check out our full review of the 2011 Infiniti M Sedan for more detail about performance, safety, comfort, and features—as well as more photo galleries and related news.