I'd argue Deja to Devil or Devil to Daisy were much bigger jumps, but I guess for a write up it must be a whole lot easier to explain the change from "immature to serious" of the first two than the actual musical evolution (abandoning the typical genre half-step down tuning for standard in order to have more options as far as key, etc.)
I also honestly don't think The Maine had such a sound shift... I think they just grew up/became serious, and if they did, the change to Pioneer or the change from the original EP were much bigger as well.
If I had to throw in a few more, I'd say Dashboard, and Hellogoodbye as two of the more extreme changes. Dashboard is debatable in wether it was for the better or worst, but it was one of the more bold moves to go full band when he was so well known for his brand of acoustic heart-on-sleeve songs, and Hellogoodbye was one of the most quality, out of left field transformations for a band. I don't think anybody remembered they existed until WYKM was released and the band was taken seriously again.