The two songs on here, Stupid Kid and The Metro, are completely different. I think that's nice. Stupid Kid is the ever popular single off of From Here To Infirmary and really increased the band's popularity. Unfortunately, I've always thought this was a very week song, and not up to par with Matt Skiba's usual songwriting abilities. That's not to say it's not a great song, because it's still good, it's just way poppier and lighter than most of the Trio's material.
Now for the second song. The Metro was originally performed by Berlin in the 80s, and is one of my all time favourite songs. This cover is very good, I think it suits the band very well and is definately worth repeated listens.
Overall, I think that buying this single is worth it for The Metro, even if Stupid Kid seems just like filler.