All plans work - it depends on what type if foods you like. If you aren't a veg fan then Extra easy will be tough, though it is the most flexible & my fav. If you can do without alot of meat, green is good, and similarly if you do without aload of carbs, red is great. If you can't face the thought of cutting bread down to just 1 large slice a day then extra easy is not for you!
I've lost over 2 stone on extra easy so far.
Its more to do with which one you are likely to stick to long term than which one you lose more quickly. SW is a lifestyle choice not a quick fix