The 3.0 V6 with 240 HP and 223 Ib. Ft. of torque is the perfect amount of power for this car, you do not have to ever worry about not having enough power for getting out of those tight city expressway situations where it demands you have a fast car "or else".
Low end power in this little 3.0 liter engine is more than apparent, cruising at 70 MPH in fairly hilly southern Indiana did not demand downshifts at all on the uphill climbs. When driving gently, you can gain speed quick at low RPMs due to having the V6 power and torque, something that's very nice to be able to do after years of 4 cylinder car's that only have power in the high RPM range.
As far as refinement; the engine may be rated low by major car reviewers, but in actual reality the engine is impressively quiet, smooth, and even sound un-differentiable from a V8 engine below 2000 RPM.
The Duratec 30 V6 engine in the Ford Fusion provides a strong and luxurious feel to the 2010 Fusion.
The ride and handling of the 2010 Fusion SEL is quite excellent. The ride is very smooth without being mushy and bouncy feeling, and handling is quite superb for a family sedan. I took it out in a parking lot and did very sharp maneuvers at 30 MPH, and the car handled it like it was born to do such things.
Interior quality is excellent, and most all surfaces in the car feel rock solid, yet soft to the touch. Leather quality is very good for a mid range family sedan, and at 9,000 miles is wearing quite well.
I question the reliability of the Ford 6F35 transmission used on the 2.5 I4 and 3.0 V6 Fusion's, as our transmission has failed almost completely as of March 26th 2010, and I've heard people talk about the 6F35 transmission in there Fusion's having strange little quirks every once in awhile, which can (and for us did) escalate to the point of transmission failure.
Despite having a transmission failure in our 2010 Fusion after having it only 5 months, I would buy a 2010 Fusion SEL V6 again if I had to.