Even when inserting an image, I prefer the appearance of the standard format with the title of the post conspicuous at the top. In either case, I am using the image as a link to a thumbnail photo gallery.
Are there differences other than the appearance of posts when using either the standard format or image format?
Is there a reason why I should consider using the image format for images?
I am using the Twenty Twelve theme. The referenced blog is private while I learn and play.
The only difference is that the title becomes less prominent and moves to the bottom of the post. If you don’t like this (I don’t, because it makes the post look like an extra section of the previous post) there’s no reason why you should use the Image format.