I finally have a complete set of jars: the Twister, the Mini-Twister and the Wildside
I use my Blendtec every day make protein shakes, but I also make hummus, sauces, batters, nut milk, dressings, and dips using whichever of the three sizes of jars is right for the task.

I made bean fudge over the holidays using my Mini-Twister jar since I didn't have the Twister jar yet, and I thought the Wildside jar was just too big. The fudge was good, but it hard to make in the Mini-Twister so that's when I decided I needed the Twister jar too.