Know what you mean, I used to look after 4 cheap rent properties for a former landlord and after the previous guy left it all went to crap and became a nightmare.
I took over and it took a hell of a lot of work to get it back to a decent place to live and I had to be so careful when letting rooms to people.
Eventually, bar a few of the troublemakers who were there from before who, to be fair, had improved a lot, things became so much better, just took a lot of time and patience.
I heard after I left things all went to crap again though :(