Canon RF 100-500mm F4.5-7.1L IS USM vs Canon RF 100-400mm F5.6-8 IS USM

Both are Canon telephoto zooms for RF full frame starting at 100 mm, but at different tiers. The RF 100-500 f/4.5-7.1 L (August 2020) is an L lens with dust and water sealing, a zoom ring with adjustable resistance and a wider aperture. The RF 100-400 f/5.6-8 (October 2021) is not an L lens, has no weather sealing according to Canon and was the first non-L lens with extender compatibility. At 635 g it weighs only about half of the 1,365 g 100-500.

In return it ends at 400 instead of 500 mm. At the long end it stays at f/8, whereas the 100-500 has f/7.1 despite 100 mm more focal length.

Which one suits whom?

• RF 100-500: You want more reach, a weather-sealed body and a little more light across the range.
• RF 100-400: You want a tele for travel and hikes that weighs little more than a standard zoom.