Both the slicers, with their default settings, printed well with minor to average problems. The major difference between the two slicers was the amount of time it took to compile the results of the G-code. Slic3r is fast in comparison to Skeinforge.
In the following image, we can see that the coin suffers from a lack of detail. It's difficult for 123D Catch to capture fine surface detail.
In the following image, we can see the results of the toy block. There's a lot of distortion caused by the 3D scanning process of the model. Both Slic3r and Skeinforge produced similar printing results.
The 3D scan of the following figure ...