time-of-flight differences? (Score 1)

Does anyone have a rough estimate about the difference in time-of-flight for an object taking the "interplanetary highway" versus the old-fasioned fuel assisted "off-road" travel? I would imagine that in some cases the fuel and gravity assisted flights, while more expensive, would be able to reach its destination faster than some of the roundabout pathways of the highway.(?) Or is the travel time difference not very substantial for an interplanetary mission because the old-fasioned travel methods involved their own roundabout gravity assists from various intermediary planets along the way to its real destination?