I've always had good luck with encargado/as, and I've lived in seven different buildings here. Although I've never had an actual portero, which I've always translated as doorman, as in someone stationed near the door at some sort of desk 24 hours a day. My encargados lived in the buildings and would clean, get the trash depending on the type of building, hose down the sidewalks, etc. At peak hours of people coming and leaving, some (but not all) of them would stand by the door or set up a chair or something, but the rest of the day they were off doing whatever they felt like I suppose.
The only kinda weird story comes from my first apartment here. My roommates and I lived across the hall from the encargada and her family. We'd throw some wild parties and they never complained, which was great. After her daughter had a baby we asked if it was okay to have another one, and she was like, yeah, of course, why would you even ask? I still love that anything goes on the weekends here. But after one party, one of the many bags of bottles that we took to the trash had broken glass in the bottom. Her teenage son, while taking out the trash I guess, cut his finger. How did they let us know? They banged on the door, we opened it and he was standing there holding his hand up, the blood dried all over his finger and hand. All they asked was that we please wrap up broken glass better, but I remember wondering why the hell they hadn't taken care of his hand before coming over. Like, the blood was dry...did he wait for us to come home so he could show us? We felt bad and apologized profusely, but like, dude, clean up your hand. We'll believe you if you say you cut it.