I lived at a property which was let by blow-me brothers for a couple of years, during which time, they did enter my property without my prior consent (much like the other commenter mentioned) a few times. Generally speaking, things were otherwise okay, up until the point at which I left the property.
Let me tell you what happened.
I left the property in immaculate condition, true to the photos taken when making my deposit. I expected my full deposit back as a result. This is where disaster struck. The agent informed me that whilst I was waiting for my deposit, new tenants had moved in, and had been burgled. According to them, this was on my head because I had misplaced a key (unlabelled and lost miles away) to the apartment almost a year prior to this happening. As a result, they withheld a large chunk of the deposit so that I could "pay to have the locks changed".
To add insult to injury, I investigated the matter myself. The new tenants informed me that there was no such burglary.
Essentially, they are a dishonest agent that will (sometimes) act friendly, but ultimately screw you over given the chance. I can\'t imagine how low they would be willing to go in a pinch.