Who should i start for wk. 3? willis mcgahee or fred jackson?

mcgahee(BAL) is playing the cleveland browns. and from what ive seen so far, the browns defense isnt that great. and fred jackson(BUF) is playing new orleans saints. some people say that fred jackson will do well in wk. 3 b/c of the saints defense, but i also think that playing against the browns is beneficial too. i understand that fred jackson is a temporary rb, but im just going to be using him for this wk if he's a good choice.