The VTK version in the ParaView “About” box needs to be taken with a grain of salt. The ParaView releases have their own VTK branch, and the “About” box reports the branch point (between that branch and VTK’s master branch). Individual patches are constantly pulled from the VTK master branch to the ParaView release branch.
I’m also interested in tracking regressions in VTK, so are lots of people. Unwanted changes in VTK behavior from version to version can be a real burr in the saddle. Studying how they occur can help us to avoid them.
Regarding the clipping, the images that you posted look like 3D cells rather than polygons. Can you provide additional details about your input data?