Take Weston around the time they released Got Beat Up (i.e., back when Weston was good), take out all the heartbroken, rainy day, "Charlie Brown gets a valentine"-esque lyrics, and take out all the slap-happy, nerd pop riffs and add a little bit of God-fearing, bible-thumping vows.
That pretty much describes The Juliana Theory.
But just because these guys sound a bit more grown up than your average pop-punk band doesn't make them as appealing as turning 40; nor do they shove God down your throat (the fact that they're on Tooth and Nail is the only significance of the Theory being a bunch of Christians).
The Juliana Theory have a better grasp on how to deal with breaking up with a loved one, rather than sitting around and feeling sorry for themselves; whining isn't mentioned in their mission statement (or it wouldn't be if they actually written one).
Just crisp, clear, and bouncy, but not to the point where "Understand This Is a Dream" crosses that line of over-produced, boring, and overly structured.