The Sloshing Machine is completely unchanged from the first game, but despite that I not only like it more, but I think it may even be my favorite Slosher now! That's probably because I've used the OG Slosher for so long that it's starting to get stale, whereas I didn't use the SM nearly as much in Splatoon 1 so it's like a breath of fresh air.
Speaking of which, the new map, while still kinda small, is atleast more open and doesn't have a raised center, making it the most distinct of the Splatoon 2 maps and my favorite one so far, yes not just because of the thematics!
-Lonely_Dolphin