Finished the dub and it's good stuff. I personally prefer it over the subs but that's mostly because I don't have to spend the majority of my time looking at the bottom of the screen when watching dubs. X)!
They did change around a few lines of dialogue and jokes (mostly the Umi puns in Season 2 Episode 5) but those are mostly due to being lost in translation anyway.
I even gave the movie a watch and it was actually really good. I liked the idea of Muse becoming nationwide celebrities (kinda reminds me of real life) and having to confront that with their initial plans for retirement. Not gonna give away anything, but just so you know, it is a satisfying conclusion.
My only complaint being the implied time travel. If you've seen the movie, you know what I mean. That lady Honoka sees is totally her future self.
But yes, Love Live The School Idol Movie comes highly recommended. At least it's better than the iM@S Movie, that's for sure.... .-.