Thoughts from those using both m43 and Full Frame DSLRs - that certain something?

thanks all, some very insightful comments coming in. one thing i'm coming to accept is i dont think i'd be entirely happy letting either system go (and should count myself fortunate i am not financially compelled to do so), at least for now. if there is some subtle quality about the images from my ful frame canon that my eye finds intuitively more appealing, it's not enough to want to carry it with me the way i do the G3 now G5. ultimate there were many images i have and will take with the G5 because i cary it with me most places whereas the canon is too much for my lower back with more than a mid sized lens attached and carrying a bag ful of the L's i own out of the question.