What @RTCool is referring to is using a couple of offsets and shift with the eraser to limit the distortion created by a softened edge.
If you just use ctrl eraser on some edges it will make your faces ugly but by using shift eraser on the other edges the distortion is contained within the lines and the edge looks rounded, without adding lots of geometry.
You should also look at The Dave Method, very useful for small details to parts of models.