In my high school days I spoke to the careers adviser about this. He explained that it's virtually glorified TAFE. He said that if I had the money, by all means Insearch was a good idea, but that TAFE was almost as good.
It really comes to two points:
INSEARCH = Expensive, but reliable (moderately so). In Insearch, there exists a good chance that you should get into your course of choice if you did well in the diploma, and the fact that you're moving from UTS to UTS helps considerably.
TAFE = The opposite of the above two points.
Of course, this is second-hand knowledge, because I have not been to TAFE nor Insearch, but careers advisers are pretty knowledgeable on these things.