Maybe it wasn’t the best idea to read this side story collection years after finishing the original manga. Or maybe it was. You see, I believe side stories should still have some merit on their own. Something more than just „oh yeah I recognize those characters from the parent work“.
Bonus Track is, in its core, just a mild melodramatical brief look into selected characters life. Slightly better than the more tame of Harlequin’s romances, but not by much. The last chapter is technically speaking a sort of epilogue, but doesn’t really do much more than the original epilogue of the original work. So, it didn’t exactly deliver on the additional value over just featuring the characters from the franchise.
The art is functional, but not the best. It has the typical lack of shading and backgrounds, and so comes off as lazy with some of the panels.
Ultimately I’m quite sure people are gassing up this title because of its relation to the franchise, not based on the content itself.