Completely different. Aside from the song with Grimes, this album has a much older feel to it. Think Phil Collins meets the Smiths meets any New York punk band (for some grit and group chants).
I've always been partial to Antonoff as a songwriter since Steel Train, so I may be biased. I also prefer his vocals to Nate Ruess'. If you like the aforementioned artists or, say, the Cars, then I would check it out. I certainly wouldn't compare to fun. though - they're a lot more theatrical and Queen-ish.