Well then, I guess that would be one small advantage of the in-lens system. Nice to be able to see exactly the effect one is getting before tripping the shutter.

Perhaps not much of an issue at the shorter focal lengths, but at long mm's the viewfinder image is so important. Like using a 10x~12x non-stabilized binoculars at a sporting event and waiting to see when/if one player says something (so you can read his lips). Very tiring to do when the image is jumping around.