When it comes to juicers you get two main types, centrifugal juicers and masticating juicers. Masticating juicers such as the Oscar Juicers use a slow grinding and crushing motion to extract juice. Centrifugal juicers such as the Breville Juicers finely grate the fruit and vegetables and use a fast spinning motion to extract the juice.
Centrifugal juicers such as the Breville tend to oxidise the juice because of the fast motion. This is why the juice is more foamy.
Masticating juicers such as the Oscar DA900 and Oscar DA1000 use a much gentler process which preserves the healthy nutrients and enzymes in the juice - this means that the masticating juicers yield a far superior, healthy juice!
The Oscar Classic juicer is the latest model - it has a larger feeding chute than the DA1000, it has two different juicing strainers and it may give you a slightly higher yield.