As Frayz said, you'll get a decent, if limited, finish from Megs 3 stage. It's okay for beginners, but you can get much better, indivdual products if you look about. This especially applies to the third stage, which is poor compared to other finishing waxes. Another problem is that none of the stages have any physical cut (stage 1 is a chemical cleaner), so if you need this, you won't get the finish you need.

As for what's better - well, that depends on the colour of the car, and exactly how good you want it to be. You'll need more than three stages for the best finish however...

Gareth