vsdiff has always had a couple nags with me:
1) This is new - if I try to diff two buffers that haven't been saved yet, I get a dialog that says "This item must be a valid path or filename" - there used to be an option to select if I wanted to diff the buffer or the file. If one or both of the files don't exist, why doesn't it just diff the buffers?
2) If I happen to type in two paths when "Compare Two Files" is selected, or two files when "Compare Two Folders" is selected, it stops and makes me go to the radio button and click it.. why doesn't it just do the right thing?