I have a set of amazing EF L lenses... due to a combination of luck and being very picky, my particular copies of the 16-35 F/4L, 24-70 II F/2.8 L, 70-200 F/2.8, 70-200 F/4, 100 F/4 macro, etc. are stellar. Even though the converter is annoying when used with my R5, the lenses are so amazing...