With Tre, I think Green Day found a style that they can move forward with and continue. Uno had some nice throwbacks to old nimrod-era Green Day, and Dos was a fun experimental album with a few more old school songs, but Tre seemed like the next step after 21st Century Breakdown. The songs are still catchy as hell and have that classic Green Day style, but the sound is a little more focused than the sound on 21CB.