Chest thump Sega tools? That's a good one.
I'll agree those games you listed for the SNES are good to great. Probably more so leaning to the good side, but that's a personal opinion. That said there's twice as many great Genesis shoot em ups. Is there where I list them all and thump my chest? But seriously I guess it comes down to personal opinion really. The way I came to this decision was in loading flash carts for both the Genesis and SNES with their shoot em up libraries. At the end of the day the Genesis has more "great" shoot em ups. And I do remember the slow down was present on more than just Gradius III.