I have had just minor problems. bad thermostat, brake calipers leaked, and a couple of interior control knobs broke on me. The biggest problem so far is that the transmition range sensor shorted out this was simple to fix.
It is very nice driving with softer suspension than most other trucks. It feels more like Crown Victoria than a pickup truck. This is my main reason for buying the f150.
I would not buy the V6 again. It has pretty good power, But The gas milleage is no better than my dads 4.6L V8. The V8 is a bit more powerful, and is a much smoother running motor.
The cruise control is very anoying. It will floor the throttle and down shift while going up moderate hills. This is dangerous on icy roads, I almost crashed because of this.
Cruise control is generally unsafe to use under icy conditions. I have never noticed any hard acceleration with my F-150.