I've used the personal cup adapter several times in the past week and I think this is a great accessory, however it does need some adjustments.  But, if you follow the instruction as outlined it does what it's supposed to do.  On the other hand, it will  leak when disassembling and you can get burned if you're not careful.  Over all I'm pleased with my purchase and will continue to use it for my protein shakes, smoothies, and almond milk.  Next I'll try to meal some flax seed using the Vitamix recipe.  Thank you Vitamix.