After just over a year happily using Sigma's RF-S 18-50mm f/2.8 on my R7, I traded it in on Sigma's new RF-S 17-40mm f/1.8 Art in August.
Yes, it's more expensive, bigger, and heavier, but wow! (It's about an inch longer and a bit less than 1/4 pound heavier than Canon's RF 85 f/2 and 28-70 f/2.8 lenses.)
Sharp at f/1.8, it's a stop and a third faster than the f/2.8 full-frame standard zooms, more than overcoming APS-C's one-stop low-light and bokeh handicaps - which is why I've given it...