yes, really no noticeable difference between these modes, it is the same for other brands of camera.

some argue that the one with higher compression will show artifacts when PP, but there is no proof. most ppl prefer fine anyway. for me i use std, can take more pic.

those who are really into these stuffs usually go for RAW.

blow up x5 times, plus in low contrast, then can see a bit difference, not that striking too, if view at 100% it'd be harder to see any diff. worth the decrease in size imo.