I'm considering hiring a companion/sitter for my dad for 4 hours a day. I have used an agency before for a short term situation, but am getting approached by many private sitters who work with other people in his Assisted Living Facility. The cost of private is lower, but is there a "catch"? I like the idea of having the "umbrella" of the agency in case there are any problems. Should I save the money and go private, or is it worth the extra for the agency to oversee the person?