Meguiar's Cleaner Wax is not bad for the price (there's a reason why it's one of their best selling waxes). It's very slightly abrasive (it has calcined clay in it) which gives it its polishing and cleaning ability, but is it as good as a pure wax or a pure polish? Nope. It's for when you want a little of both and don't want to have to do both separate steps.
Their GC wax is carnauba-based and is known for making colors more warm and deep, especially dark colors. This also has a little bit of calcined clay in it so it polishes very slightly.
Their ultimate wax is longer lasting than any of their other waxes and it's known for making very good reflections (but not changing the shade of colors like GC does). This too also has a little bit of calcined clay in it so it polishes very slightly.
I currently use their GC wax when I want the car to look good during the summer, when I want protection before the season changes I go with something longer lasting and synthetic like Ultimate Wax or Turtle Wax ICE.