I didn't think chasing was more difficult that setting at target in ODIs. The conventional wisdom I had always heard was that chasing is marginally better for a day game and worse for a day-night.Am I wrong in saying that good chaser is usually valued above other batsmen?? At least this seems to be the perception among majority if not all the fans as chasing is considered to be more difficult task than setting the target.
Other than that, it seems like setting or chasing is a preference that each team has. For example, in the last 10-15 years Australia has generally preferred batting first whereas India seems to be the opposite, which is probably a function of how confident the team is in their batters' ability to chase a big score relative to their bowler's ability to defend one under pressure.