I blame the lack of pass view (I am not the first) and I especially do not like keeping system dia by two small springs slide. It's long to position the slide. A system of side rails to slide the dia would have been helpful, all the dias cached making 5x5 cm.
Otherwise, associated with the macro lens 40 mm Nikon DX, the results are good, especially if we correct the slide with good software. It even recovers slightly split or funds can result dark areas with Aperture or DXO.
With this principle of recovery of a photo dia, surely the system offering the highest speed and best quality.