Up to now, when colour correcting, I have used the 3-way colour corrector, are there things that the other cc tools can do that the 3 way can't? or are they all slightly different versions of each other.
Summary: the 3 way corrector is another view of the Levels adjustment (same math, different UI). Yes, the other color adjustments can do much more than the 3 way corrector.
Long version: go play with all the other adjustments, or read up on what all of them can do. You've been missing out on a lot of possibilities.