The Canon RF 28-70mm f/2 USM L is everything that you can expect from it - it is a monster of a lens with a monster performance. This is especially true for the broader center quality, which is as good as on the best prime lenses. The outer image field is also superb in the lower zoom range. The corners soften a bit at 70mm but remain easily on a good level. That's on a 45-megapixel sensor. On 20 to 30 megapixels, the lens is almost perfect. The native image distortions can be noticeable at 28mm but are not an issue beyond. The native vignetting is quite high at f/2, but that's no different from prime lenses. Auto-correction comes to the rescue in both cases, of course. Lateral CAs are absolutely negligible. The quality of the bokeh is good, but there is a little room for improvement here. However, that's complaining on a very high level, really. The rather massive focus-breathing isn't ideal for videos, though.

The build quality is excellent, which isn't surprising given its professional target audience. The materials and assembly quality are top-class. Weather sealing is a natural feature at this price point, anyway. Some may not like the extending zoom mechanism - but this is just normal for pretty much all standard zoom lenses. A bigger question mark may be around the handling, though. The lens is huge, and using the big zoom and focus ring isn't quite as comfortable as on the RF 24-70mm f/2.8 USM L IS. You may argue that this isn't any different from fast tele lenses, but the RF 28-70mm f/2 will be used mostly hand-held and, as such, it is front-heavy and unbalanced.

If you want the very best and fastest standard zoom lens, there is, the RF 28-70mm f/2 USM L is the one to go for - at least for photographic purposes. However, you should ask yourself whether you are ready for it. This just isn't your average fast standard zoom lens. It will leave you in awe, but as with all monsters, you will feel it after having battled with it for a long day.