As we've grown accustomed to fairly high pricing on most RF lenses, we have learned to cut Canon some slack on this front, knowing that they are releasing lenses that are not only state of the art but a cut above. Looking at reviews on some of these lenses, RF 85 1.2L, RF 28-70 F2L, etc, I find myself drooling over their sharpness. Even the moderately priced RF 24-105 F4L is getting great reviews. Eventually, as the RF line seasons, we'll see some sort of price breaks, albeit I don't expect any bargains any time soon, even for Black Friday. Come on Canon, Adorama, B&H, surprise and shock us.
So, it turns out that it really is almost as fat as the f/2.8. I don't really understand why it needs to be, but I never liked the long thin EF 70-200/4L/IS/ISII so I'm not complaining. If I was in the market for a 70-200 this could be a very attractive option.
My guess is that the extension mechanism takes up a significant portion of the width. Or Canon follows the EF-M mantra with marketing based sizes and will only allow chunky L RF lenses.
DOF difference is not that huge. There will of course be cases, where you can see the difference, if the background is "close" enough. Check out the flickr 70-200mm f/4 pool and see if you think it will matter to you. Other will have a hard time deciding for you. I got the EF f/2.8 - but only because I needed the extra speed.
Wow, just noticed how ugly it will look when you put on the shade. No wonder Canon is not showing us this.
