Canon announced this lens shortly after I acquired my R8 body, and if it had been available at the outset, it would have been a strong contender for my first RF lens (I ended up going with the 50mm f/1.8 STM). I'd been eager to get my hands on one since they were released, and finally bought one about a month ago. I've now put it through its paces, and have formed a pretty strong impression of it.
I imagine that, if you're drawn to this lens like I am, the main reason is the diminutive size and weight. That, coupled with the super useful 28mm focal length, which is wide enough for easy indoor use with my kids and friends, but not so wide that I need to get all up in their space when photographing them, has almost instantly made this my primary lens. The f/2.8 maximum aperture coupled with the still mind-blowing-to-me high ISO performances of modern mirrorless bodies makes it usable in less-than-ideal lighting as well.
The form factor is the true star here. It's ridiculously tiny and light. On my R8 body, the whole system weighs less than 600g with battery and card, and it's so small I can fit it in the pockets of my parka when I'm out for a walk. It's so light and well-balanced that I can hold it easily down low to the ground to exaggerate scale, or up high to capture more of a group scene. The flexibility of having such a tiny camera and lens cannot be overstated.
My main criticisms are the movable inner barrel, though that's no different than some of the other small non-L primes Canon has released, like the RF 50mm or 16mm. It feels a little exposed and at-risk, but given just how small this lens is, even when it's fully extended, it's not really any further out front than my knuckles are on the grip of my body, so knowing where it is in space is easy. I also find the price to be a bit high, considering where the older EF pancake lenses sit right now. I say this though with the understanding that this is still a new product and they decidedly are not. I still think this lens is a solid value that really excels in its mission.
One other thing I'd like to highlight as a positive is the controls. For such a tiny unit, they're very useful. Compared directly to, say, the RF 50mm, the controls on this really nail the balance between function and cost-consciousness. I find the "Focus/Control" switch on the 50mm pretty frustrating, because I still have to delve into menus to actually turn on manual focus. However, the "Auto/Control/Manual" switch on this RF 28mm nails the simplicity/cheapness of only having one switch, but filling it with functionality, given that it can be set to autofocus, autofocus with the control ring active, or manual focus, all on the one switch on the lens barrel without having to access any menus. This, I think, is the ideal setup for the simpler/cheaper RF lenses that only have one control ring to share between focusing and other control functions. Please let this be the model for future non-L lens designs.
I've included a few sample images here. By far the majority of photos I've used this lens for have been indoor photos of people, but using photos of my kids or my friends in an online review isn't for me, so I've tried to select some the show the possibilities of using this for landscapes, streets, and even close-ups with soft backgrounds (just pretend the dried flower is someone's face - lol). All in all, I could not be happier with this lens. I'd buy it again in a heartbeat.