Just get inside!
This is the second time we have stayed at the Hotel Metropolis. We do like the two bedroom rooms that have a living area in the middle. Perfect for kids or groups. 
The hotel itself is clean and well taken care of. The employees are nice and helpful. The adjoining restaurant is a fine soul food spot. Worth the eats! Great drinks as well. It's a quick one block walk to Union Square and for the price it will save you well worth it! 
Now you ask about the one star ratings...some folks forget this is San Francisco and strange stuff lurks in the corners. There are indeed a savory group of homeless around the area but the hotel itself is free of them and never once have I felt unsafe in this hotel. I have even walked in and out at night and was not bothered by the folks outside. Like I said it's the city.