i saw your post that you have the ffg;

reverse rings, macro extension tubes, ring flash/ light reverse rings, macro extension tubes, ring flash/ light

i do have kenko extension tubes. i used it with my 50mm f1.8. its gives better result than my 60mm macro lens. but. its very slow to auto focus. sadly i cant or dont use manual focus. the 60mm macro lens. makes shooting easier compare to manual or using extension tubes. about the sharpness. using said reverse ring and ext tube with a prime lens could or might give a better result :)