This plugin is generally very helpful, but I think it does more harm than good when looking at vimdiffs. Diffing two files in vim will highlight added lines as blue, removed lines as red, and modified lines as purple.
Enabling cursorline overwrites the line's diff-color, making it hard to tell if the current line is added, removed, modified, or unchanged. This can be worked around by using :ConoLineDisable, but it would be nice if the plugin had a configuration for automatically disabling for diffed files (these buffers have &diff == 1, so it should be easy to check immediately before setting cursorline).
This could either be the default behavior, or an option that is off by default, I would be happy either way. If you're interested in this feature but don't have the time to implement it, let me know and I can investigate.
Cheers, and thanks for the plugin!