Conclusion: This is a superb lens if you are a macro/micro photography enthusiast. It is kind of tricky to focus since, well, you can not focus with the lens. You need to move the camera in order to get the right picture. It is definitively not for everybody, this is only if you like this type of abstract photography and, since it is not cheap, you may want to rent it first. In my case, I can not be happier it is really fun to use and so far no need of a tripod to take awesome pics.
Conclusion: If you love macro photography, this lens takes it to another level. There is an initial learning curve with it, but once mastered it truely opens the door to insane macro ability. Lighting has been an issue, at the 5x magnification, due to the shallow distance from the object. I have been experimenting with light painting as a means of highlighting areas with good results. Live view, tripod, shutter release are highly recommened. A great lens to own.