Well, it's about time isn't it?
I finally added Steam Cloud, as for the login system, that'll still have to be there. Although on the bright side you're not forced to login to PlayFab anymore and have your save data be erased if you weren't registered. Yeah, that's about it.
Also the reason I've decided to use PlayFab is to prepare whenever I'm going to port the game to app stores. But I've probably should've implemented this first... sorry. ːsteamfacepalmː