When you're thinking about traditional 50mm field of view and the options between full frame and Micro Four Thirds, these two lenses sum up your choice pretty well. Both optics will provide excellent image quality. Softer backgrounds will be easier with the Canon because of the larger sensor. Both lenses qualify as professional gear. But what a difference physically between the two... and price.
The Canon RF 50mm f/1.2L USM currently runs $2,099 and weighs 950 grams.
The Olympus M.Zuiko Digital ED 25mm f/1.2 PRO is selling for $1,099 and weighs in at 410 grams.
(Because of its smaller size, a 25mm optic on a Micro Four Thirds sensor presents an equivalent field of view to a 50mm lens on a full frame chip.)
I'm not advocating one over the other. But what I do want to point out, and what isn't discussed as much these days, is that you have some distinct options in price and weight for high level photograph gear.
You can share your thoughts at the TDS Facebook page, where I'll post this story for discussion.