They speak broken swedish with horrible accent. I have multiple finnish-swedish cousins and extended family, and they don't really understand actual swedish very well. And the area typically drawn on map doesn't really tell anything, its the amount of people that matters, and thats not a lot. 4,78% of population. You have almost as many people from Syria there as we have finnish-swedes, and about half the amount of "swedish-finns" in there. There are basically couple of tiny villages here (~1000 persons) which are almost 100% "suomenruotsalaisia" (finnish-swedes) who also really don't speak finnish or speak it at same level as your typical Finn speaks swedish. In other cities and towns they speak mainly finnish and then broken swedish among themselves.
Åland is different though, and its mainly swedish. If it were up to me I would donate it to Sweden. It's nothing but moneyhole for us. Mainlanders can't even purchase property from Åland, and they are not drafted to military like regular folks.