Exactly one year ago (December 18, 2018) I received my first Blendtec.  It was a Total Blender Classic with 10 speeds, pulse, six presets, and a four-sided jar.  I loved it!  The only thing that it did not do perfectly, however, was make nut butters.  Because I am somewhat of a health-food addict, I love to make my own nut butters; and after reading some reviews and watching some videos of the twister jar, I decided to give it a try.  I am absolutely THRILLED!  In 50 seconds I can make perfectly smooth nut butters with no added oil.  I heartily recommend this jar to anyone wanting to make healthful nut butters.  So far I have not tried to make other types of food with this jar, and I still use the four-sided jar for fruit smoothies and protein shakes.  The combination of the four-sided jar and the twister jar is definitely a winning combination for all health-minded persons.