> I would like to have some feedback on the changes, but it seems I won't
> get some, so I better test some more myself first.

Well, the basic thing both thumbs packages are still missing is proper
integration with dired.  The first thing I expect from a thumbs package
is to display a dired buffer with thumbnail images in it.

This can be very easily done with iimage.el, i.e. just open a dired buffer
and type M-x iimage-mode RET and you will see, for example: