Aside from the extra effort required to push everything around, the centre of gravity will change as will the steering stability. How much that gets affected really depends on the geometry of the frame and how you distribute the weight. You might want to visit the touring forum. 230 lbs is OK as long as the wheel build is suitable and you keep your speed down over rough roads. Touring bikes tend to have heavier, stronger frames than straight recreational bikes in anticipation of an extra load. Suggest you also check the load rating on your tires and adjust the tire pressure accordingly.