As of 2015, a good place to find a comparison of juicers is the Everything Kitchens site. The site offers a comprehensive comparison of over 40 juice machines.
The Everything Kitchens site compares the ease of cleaning, feed chutes, power, RPM and warranty. Pictures are provided for each juicer, and the products can be purchased on the site. The brands compared include Breville, Omega, Kuvings, Hurom, Champion, Tribest, Samson and Waring.
Another good location for juicer comparisons is Discount Juicers. The site compares many aspects of each brand, including the quality of juice produced, feed chute size and shape, yield and horsepower.