One thing that Nemo/Nautilus/Caja have is the ability to show embedded mp3 artwork instead of the standard "music" file while browsing your music files. On those file managers the Totem package or Mint's X-player package must be installed which actually generates the thumbnail while browsing the files within those file managers. On Thunar, the thumbnail is not generated with or without Totem/X-player. However, if you have another file manager like Caja installed in XFCE (along with Totem or X-player) and you open a music file with Caja, the thumbnail is generated within Caja and that generated thumbnail will also show in Thunar, but it must be generated in another file manager first (in this case Caja).
When I'm editing my music files (changing ID3 tags/adding embedded artwork) I have to use Caja on XFCE to actually see if the artwork "took" to the file. Thunar generates other media thumbnails (movies, pictures), but not music. I definitely would like to see future builds of Thunar be able to generate those thumbnails like the other file managers do.
The best way to lodge feature requests is to file a request at https://bugzilla.xfce.org/. Few developers visit here. That said the current focus is on porting to GTK3, new features aren't a priority at the moment.