If you're reading this, then probably want to learn more about the masticating juicers, how they work and what they're good for.
Based on my experience. masticating juicers perform way better than centrifugal for leafy greens and hard fruits and vegetables. They produce a lot more juice yield and generate almost dry pulp. However, they get clogged when you're trying to juice citrus fruits like oranges, lemons, etc.
Masticating juicers work very slow, mostly around 80RPM because of the technology used to produce the juice. Fruits are slowly pressed by the auger to ensure maximum juice extraction. Some models even have dual-stage augers which improves their performance and the juice yield even more.
As a bottom line, if you are going to juice mainly leafy greens like celery or wheatgrass you should get yourself a masticating juicer. They cost more but in the long run will save you money, since you produce more juice.
You can find many comparisons and user reviews about the best masticating juicers you can get.