This is great plugin, works really well in my case for showing next and previous links in custom post type that is sorted on a custom field.
One thing I would like to do but can't see a solution is to add the value of the custom field to "before" the link. So as an example instead of "article 2" as the link I would see "3.01 Article 2"
To recover the value of the next and previous links in the custom sort I would need to recover the ID of the next and previous posts and I wonder if there is a way to do this from this plugin? Once you have the post ID you can get the meta value and I assume prefix it to the link.
There are template tags for getting adjacent posts but it appears to me that they work on chronologically sorted posts so that don't offer any help. Unfortunately my skills don't run to writing a function to do the job.