Spinning rods require larger guides as the line comes off of the spool. Spinning rods don't require as many guides as a casting reel, as the line on a spinning reel is pulling "below" the rod when you are fishing. Spinning rods are often the best type to start with for casting baits, as they are less prone to tangles for inexperienced casting. Some techniques are best served with a spinning rod for finesse tactics. It really is going to depend on the fishery and the type of retrieve/jigging action.