Excerpt: Everything you could ask for in a Macro lens. Works exactly as eve one describes. Coming from the 100 macro you get much more focal length and even sharper. It is worth the money to just start with this lens instead of trying to finds a replacement. It just won't hopped If you are looking for a long focal length macro lens. Canon 180 3.5 L will not disappoint you at all. Little tough to hand hold but that is why there is mono pods and tripods.
Conclusion: Of course, macro is always with tripod or also with some focus adjuster. When this is heald steadily, images come up amazing. Again, you should balance depth of field with speed according to what the light allows!
Summary: This is a great lens. I've used it to capture pollen in tiny wildflowers! I would, however, recommend also getting a macro flash of some sort - f32 really limits your light. If you don't have a flash you either need a still subject and a tripod, or full sunlight.