I have done similar tests on my own copy and can confirm that it does indeed cover the full frame from 15-16mm. The hood makes little difference.
IQ does drop a bit in the corners, and the corners are a bit darker on full frame than the equivalent focal length on crop. I would not use it on full frame if I had a crop body available.
Sharpness in the centre is outstanding from f/2.8. The corners are never fabulous at 11mm, even stopped well down, but that improves rapidly when you zoom in a little.
Images can be seen
HERE
Bottom line: given the size and weight difference, and filter factor, I reckon I'll be selling my DFA15-30.