I have been researching smoothie makers, specifically the back to basics smoothie elite, smoothie pro 600, and smoothie pro 700. I am trying to figure out if they are any good. There are tons of reviews on line, but people either love them or hate them! I was wondering if any dis board members have any experience with any of these, and would they spend the extra money for the more powerful motor in the smoothie pro 700?? Thanks!