The I4 Malibu seemed lacking power in low RPM range. I had put a bit force on the gas padel when backing out while parking, which is a big hassle, and can be unsafe if the space is tight. I car moves at higher RPMs really well. Since I had a rental, I floored it all the time, even hit the red line couple times. The car seemed to move really fast after you get abover 3000 RPM.
I would imagine the V6 is a lot better to drive. My best friend had one for awhile, he likes it. But I personally never drove a V6.
You can just go to any dealer and test drive yourself, and find out.