
While it's not a lens that I would use on a regular basis, I have seen some extremely well done shots with a fisheye... and therefore I would not discount this type of lens...
Photos that were about content not fisheye rendering... e.g. the Milky Way with old buildings, interiors, and very narrow canyons.
I look forward to seeing how your time with that lens develops... I think you have to experiment to get the most out of it... but I like what you have shown us here...
Casey