In my experience, it all depends on who you outsource with (and your own level of knowledge). Understandably, a total novice to the administration process is probably more suited to getting a second opinion when it comes to the standards of their systems, because business-people are sometimes all too happy to take un-educated clients for a ride.
I would recommend getting other peoples opinions beforehand and asking the support company for information about which other client's systems they administer. There should always be someone you can get a second opinion from...but try and get it before you let the company get their dirty paws on your beloved PC's...
~Equinox