Here is a summary of what Cook's Illustrated said about convection ovens....
"Convection settings do promote even browning and work well for preparations in which browning and crisp surfaces are desired. Temperature reduction is necessary for more delicate and sugary baked goods such as cookies and tart shells but not for sturdier, more savory foods such as roast chicken and yeasted breads."
With so much depending on the oven and the type of food being cooked, there is not a universal answer that will work in all circumstances. It is important to know your oven and to watch for visual clues that an item is done and not to rely fully on the times given in recipes.