If you want to get the auto, definately get the V6. I used to have a 6th gen auto 4 cylinder and I'm pretty dissapointed with the performance. It's slow and the auto is not slow to shift.
I've driven the V6 and it's much better imo. You'll feel the additional torque. And the car doesn't feel that heavy compared to the 4 banger.

So, if you want to get auto, get the V6 I regret getting the 4cyl auto. If you want to get the 5 speed, then get the I4.