I was wondering if its possible to somehow implement a feature I had in foobar2000.
the statistics for a song (rating,play count, last played) were saved on a per-song basis based on tags and not per file. this is quite helpful when you have different versions of the same album, let's say mp3, flac, ogg, etc.
is it possible to do something like this with gmb?

another quick question, I can export those statistics from foobar2000 as an xml file. is there a way to import them into gmb?

thanks for any info. 

sharing statistics for same songs : it is not currently possible. Storing them on a per-song basis will not be possible, but there are other ways I think. I guess it wouldn't be too hard to write a plugin that when one song's statistic change, search and update other "same" song. Though I really think the library should only contain one version of a song. Such a plugin could also be useful for identical songs that are present in an album and a best-of or a single, I usually prefer deleting these, but I still have a few, though it could be hard to differentiate these identical songs from live versions or remix.

About importing these values from an xml file, there is no existing script that I know of, but it should be easy to write one.
Here is an example script to set the playcount for a given file via DBus : https://gist.github.com/2422493
It works the same with the fields lastplay and rating. lastplay must be given in seconds-since-01-01-1970, and rating as a 0-100 integer.