For my macro interests, the size of the smallest subject that I can fill the frame with is more important than the arbitrary goal of “life size on the sensor”, and minimum field size is what measures that. For example, with 35mm film format, 1:1 macros fills the frame with a 36x24mm subject, whereas in Four Thirds, 1:2 does about the same: field size 35x26mm. The traditional 1:1 or other magnification measures make sense when comparing cameras in the same format (or with films of equal resolution?), but not do much when comparing cameras in different formats and sensors of different resolution in lines/mm.
I have and love the Olympus 60/2.8 macro, but rarely go all the way in to its 1:1 at minimum focusing distance which gives a tiny 17.3x13mm field size. But I can see how you might enjoy that extreme close-up option, equivalent to what you get with 2:1 “twice life size” macro in 35mm format.