from the way you say they sat next to you suggests that you are talking from purely an ac point of view, is that correct?
In tc, in my experience, some of our atsa are brilliant, and can't do enough for you and it is really appreciated, they really earn their money and take pride in their profession. others are no better than dog toff and it can make working a sector more awkward than it should be. in the past i have contemplated splitting a sector earlier than necessary to accomodate for poor atsa work.
A good atsa is as good as a coordinator (sometimes better) for the help they provide to the operation.