Cold air is always good but I agree you won't see any giant leaps in overall driving performance.
As far as the ram air effect, about a dozen or so years ago one of the more credible engine builders did some tests and found out it did nothing until the vehicle had passed 90 mph and then it only added about a 1 to 1.5% gain in hp. He also reported that depending on the twists and turns in the cold air duct most factory ram air packages showed no difference from ram effect and only from the cooler air and even this was minimal because the ducting ran so close to hot parts on the way to the carb.
The most effective results came from a plenum box at the base of the windshield like is done on NASCAR stock cars, or from a big old scoop on top of the carb sticking out through the hood.
