I love Add an image for the nice frame and caption it provides (Add Media From URL).
Using Umlauts directly (üöä) supresses the frame and the caption. I used ü which then translates. However, re-editing the post causes the code to be displayed as an umlaut again, so I have to re-edit all the umlaut captions as well, a real hassle.
2) Feature request
It would save a lot of time if the "Alternate text" and "Image Caption" were copied from the "Image title" upon losing focus, since these texts are normally the same for me.