Originally Posted by IS3andME
V6's are inherently unbalance---needing balancers...they are course and rough...there probably is a good reason why Nissan probably will be using Merc's 3.5 liter V6's, due their issues with the VQ V6 (which are the best sounding V6's).
I6's are far more smoother---there is a reason why BMW, Merc, stuck with them for a long while. And why Nissan's RB series I6's and Toyota's I6's are damn near legendary for their smoothness and Hulk like strength.
I guess the real argument for the V6 is the configuration is more compact than a I6, and they can just shave the first 2 cylinders off of the V8 for a cheaper engine.
60 degrees V6 is inherently balanced, as it is inline 6. 90 degree V8, 72 degree V10.