Just announced. New toy!
And I do not mean to belittle this lens. The specss and MTFs look great.
What may be interesting to me the most is that it seems Canon has quietly populated an upper-mid tier set of non-L lenses. Specifically, the RF 16-28 f2.8, RF 28-70 f/2.8 and the RF 100-400 for zooms. For primes, Canon has always had some nice non-L primes (EF 24 f/2.8, 85 f/1.8, etc) but they certainly have carried that forward with a nice population range from the 16 f/2.8 (I own, nice lens), 24, 28, 35, 50, and 85 mm variants.
But the zooms, they are making me think back to the EFs 17-55 f/2.8. I opted for focal length range and the EFs 15-85, but both were optically great non-L lenses.
Anyway, new lens. Specs and MTFs look great. I can see a lot of advanced amateurs (even a few others) going this route.