All cameras are not created equal -- not even all EOS Ms. Sure, each of the four compact flavors may carry the same 18-megapixel APS-C CMOS sensor, 1, 040, 000-dot 3-inch touchscreen and arguably mediocre UI, but only one has a remotely premium shell.
ENGADGET: Canon EOS M review: was Canon's first mirrorless ILC worth the four-year wait?