When I printed this object (http://www.thingiverse.com/thing:40635) from thingiverse I saw that when my printer was printing the outer shell, the head wasn't moving smooth. It hesitated for a moment on each layer.
The finished print shows a lot of blobs on the surface of the object.
I tested the 'TEST2' version from this threat and the results are better, but on some layers the head still hesitates and therefore there are still blobs on the surface of the objects.
edit by gr5: Made image link better.